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TRANSCRIPT
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2nd Grade
Three Digit Addition and Subtraction
2015-12-01
www.njctl.org
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Table of Contents Click on the topic to go to that section.
Three Digit AdditionAddition with Regrouping Ones
Addition and Subtraction Word Problems
Addition with Regrouping Ones and Tens
Regrouping Part 2
Three Digit SubtractionSubtraction with Borrowing from the TensSubtraction with Borrowing from Tens and HundredsSubtraction Across Zeros
Lab: Dice Addition
Lab: 1000 Wins
Slide 4 / 157
Standards for Mathematical Practices
MP8 Look for and express regularity in repeated reasoning.
MP1 Make sense of problems and persevere in solving them.
MP2 Reason abstractly and quantitatively.
MP3 Construct viable arguments and critique the reasoning of others.
MP4 Model with mathematics.
MP5 Use appropriate tools strategically.
MP6 Attend to precision.
MP7 Look for and make use of structure.
Click on each standard to bring you to an example of how to meet
this standard within the unit.
Slide 6 / 157
When adding, it is VERY important to line the numbers up on top of each other.
1 6 52 3 2+
One
s
1 6 52 3 2+
Tens
Hun
dred
s
The ones must be lined up, the tens must be lined up and the hundreds must be lined up.
165 + 232 =
Three Digit Addition
Slide 7 / 157
Once the problem is lined up correctly, add the ones column first.
One
s
1 6 52 3 2+Te
ns
Hun
dred
s
Three Digit Addition
Slide 8 / 157
7
Next add the tens.
One
s
1 6 52 3 2+
Tens
Hun
dred
s
Three Digit Addition
Slide 9 / 157
9 7
Last, add the hundreds.
One
s
1 6 52 3 2+
Tens
Hun
dred
s
Three Digit Addition
Slide 10 / 157
PracticeLine up the number and then add
6 4 3
+ 2 5 6
Slide 11 / 157
PracticeLine up the number and then add
2 3 3
+ 7 4 5
Slide 12 / 157
PracticeLine up the number and then add
6 1 4
+ 2 7 4
Slide 13 / 157
Write the addition sentence correctly on your paper
9 2 3 + 1 6 4
Lining up the Digits
Slide 13 (Answer) / 157
Write the addition sentence correctly on your paper
9 2 3 + 1 6 4
Lining up the Digits
[This object is a pull tab]
Teac
her N
otes
Have students write the addition problem on a piece of paper or on a slate. Check to make sure the numbers are lined up. Then have them
add. Have a student come to the board to model what they
did.
Slide 14 / 157
When adding 100 to any number, the ones and tens stay the same and the hundreds just
go up 1.
5 6 8+ 1 0 0 6 6 8
How is adding 100 like adding 10?
Adding 100
Slide 14 (Answer) / 157
When adding 100 to any number, the ones and tens stay the same and the hundreds just
go up 1.
5 6 8+ 1 0 0 6 6 8
How is adding 100 like adding 10?
Adding 100
[This object is a pull tab]
Mat
h Pr
actic
eMP3 - Construct Arguments
Have students discuss as a class the differences and
similarities between adding 100 to a three digit number and adding 10 to a two digit
number.
Slide 15 / 157
Remember, just go up 1 in the hundreds.
393 493
742 ______
400 ______
236 ______
Adding 100
Slide 16 / 157
Practice
700 + 200 = ______
What addition fact could help you solve this problem?
Slide 16 (Answer) / 157
Practice
700 + 200 = ______
What addition fact could help you solve this problem?
[This object is a pull tab]
Mat
h Pr
actic
eMP.2 - Reason Abstractly and
Quantitatively
Give students a chance to think about addition facts. Call on a
students to explain 7 + 2 = 9, so 700 + 200 is 900.
Slide 17 / 157
1 The addition problem below is lined up correctly.
True
False5 2 8
+ 1 5 1
Slide 17 (Answer) / 157
1 The addition problem below is lined up correctly.
True
False5 2 8
+ 1 5 1
[This object is a pull tab]
Ans
wer
False
Slide 18 / 157
2 Which place do you add first?
A ones
B tens
C hundreds
Slide 18 (Answer) / 157
2 Which place do you add first?
A ones
B tens
C hundreds
[This object is a pull tab]
Ans
wer
A
Slide 19 / 157
3 Add
7 3 1
+ 1 0 0
Slide 19 (Answer) / 157
3 Add
7 3 1
+ 1 0 0
[This object is a pull tab]
Ans
wer
831
Slide 20 / 157
4 Add
2 4 5
+ 3 2 2
Slide 20 (Answer) / 157
4 Add
2 4 5
+ 3 2 2
[This object is a pull tab]
Ans
wer
567
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5 Add
1 0 0
+ 2 5 2
A 152
B 352
C 251
Slide 21 (Answer) / 157
5 Add
1 0 0
+ 2 5 2
A 152
B 352
C 251[This object is a pull tab]
Ans
wer
B
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Slide 23 / 157
Slide 25 / 157
Regroup means to take apart a number to write it in a new way. We can regroup 14 to 1 ten and 4 ones.
We can regroup 28 to 1 ten and 18 ones.Regroup
Slide 25 (Answer) / 157
Regroup means to take apart a number to write it in a new way. We can regroup 14 to 1 ten and 4 ones.
We can regroup 28 to 1 ten and 18 ones.Regroup
[This object is a pull tab]
Teac
her N
otes
What does regroup mean? Ask students when they have heard this word before. Ask for some
students to explain what it means. Click on the word to
show the definition.
Slide 26 / 157
Steps for Adding with Regrouping
1 ~ Add the ones
13 4
+ 25 610
Slide 27 / 157
Steps for Adding with Regrouping
2 ~ If it's 10 or more, bring the tens next door.
13 4
+ 25 610
1
0
Slide 28 / 157
Steps for Adding with Regrouping
3 ~ Add all 3 numbers in the tens place
13 4
+ 25 6
1
09
Slide 29 / 157
Steps for Adding with Regrouping
4 ~ Add the hundreds place
13 4
+ 25 6
1
093
Slide 30 / 157
Practice
2 4 5+ 3 3 7
Start on the right to get the problem
right!
1 ~ Add the ones
2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens
4 ~ Add the hundreds
Slide 31 / 157
1 3 6+ 4 2 6
Start on the right to get the problem
right!
1 ~ Add the ones
2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens
4 ~ Add the hundreds
Practice
Slide 32 / 157
4 2 8+ 5 4 5
1 ~ Add the ones
2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens
4 ~ Add the hundreds
Practice
Slide 33 / 157
4 2 8+ 5 4 5
How would you start this problem?
Slide 33 (Answer) / 157
4 2 8+ 5 4 5
How would you start this problem?
[This object is a pull tab]
Mat
h Pr
actic
e
MP.1 - Make sense of problems and persevere in solving them
Give students a chance to think about the necessary steps to solve a three digit addition problem. Have
them explain how to start it to a partner and then pick someone to explain it to the class. Continue having them explain each step.
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8 1 9+ 1 6 5
Practice
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6 If it is ten or more, bring the ones next door.
True
False
Slide 35 (Answer) / 157
6 If it is ten or more, bring the ones next door.
True
False
[This object is a pull tab]
Ans
wer
True
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7 Would you need to regroup if the ones place was
6 + 8?
Yes
No
Slide 36 (Answer) / 157
7 Would you need to regroup if the ones place was
6 + 8?
Yes
No
[This object is a pull tab]
Ans
wer
Yes
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8 Would you need to regroup if the ones place was
1 + 8?
Yes
No
Slide 37 (Answer) / 157
8 Would you need to regroup if the ones place was
1 + 8?
Yes
No
[This object is a pull tab]
Ans
wer
No
Slide 38 / 157
9 Add
3 2 8
+ 6 5 7
A 975
B 985
C 9715
Slide 38 (Answer) / 157
9 Add
3 2 8
+ 6 5 7
A 975
B 985
C 9715
[This object is a pull tab]
Ans
wer
B
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10 Add
5 7 9
+ 2 1 8
Slide 39 (Answer) / 157
10 Add
5 7 9
+ 2 1 8
[This object is a pull tab]
Ans
wer
797
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Slide 41 / 157
Slide 43 / 157
Steps for Regrouping
5 8 5+ 1 4 8
Start on the right to get the problem
right!
1 ~ Add the ones2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens4 ~ If it's ten or more, bring the tens next door
5 ~ Add the hundreds
Slide 44 / 157
Practice
6 4 8+ 2 7 4
Start on the right to get the problem
right!
1 ~ Add the ones2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens4 ~ If it's ten or more, bring the tens next door
5 ~ Add the hundreds
Slide 45 / 157
Practice
3 5 5+ 4 8 5
Start on the right to get the problem
right!
1 ~ Add the ones2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens4 ~ If it's ten or more, bring the tens next door
5 ~ Add the hundreds
Slide 46 / 157
Line up the numbers and then add
5 9 3 + 2 5 8
What tools could you use if you got stuck?
Lining up the Numbers
Slide 46 (Answer) / 157
Line up the numbers and then add
5 9 3 + 2 5 8
What tools could you use if you got stuck?
Lining up the Numbers
[This object is a pull tab]
Mat
h Pr
actic
e
MP5 - Use appropriate tools strategically
Ask students about different math tools (number line, base-ten blocks, number grid, etc.). Have students
explain how they could use different tools to help them
solve this problem.
Slide 47 / 157
Line up the numbers and then add
2 3 9 + 5 6 7
Lining up the Numbers
Slide 48 / 157
11 Add
7 3 1
+ 1 9 9
A 930
B 920
C 830
Slide 48 (Answer) / 157
11 Add
7 3 1
+ 1 9 9
A 930
B 920
C 830
[This object is a pull tab]
Ans
wer
A
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12 Add
2 5 2
+ 6 5 1
A 903
B 913
C 803
Slide 49 (Answer) / 157
12 Add
2 5 2
+ 6 5 1
A 903
B 913
C 803
[This object is a pull tab]
Ans
wer
B
Slide 50 / 157
13 Add
3 7 9
+ 2 3 2
Slide 50 (Answer) / 157
13 Add
3 7 9
+ 2 3 2
[This object is a pull tab]
Ans
wer
611
Slide 51 / 157
14 Add
5 2 6
+ 1 7 4
Slide 51 (Answer) / 157
14 Add
5 2 6
+ 1 7 4
[This object is a pull tab]
Ans
wer
700
Slide 52 (Answer) / 157
Lab: Dice Addition
Click to return to Table of Contents
Teac
her N
otes
[This object is a teacher notes pull tab]
Roll the 3 dice by clicking on each dice. Have a student come to the board and write the 3 digits on the first line of the problem. Then have another student roll the 3 dice again and write the 3 digits on the second line.
Have all the other students write the addition sentence on their white boards and then solve it.
orHave students play a modified version of this game with
a partner.1 - Roll 3 dice and write a 3 digit number using the three
digits you rolled (ex: 3, 6 and 2 can be 236, 326, etc.).2 - Write the number as the top addend.
3 - Roll the 3 dice again and write the number as the bottom addend.
4 - Add the two numbers using the steps to addition with regrouping.
* Have both students write the addition sentence and check to see if they have the same sum. If not have
them work together to find their mistake.
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Slide 56 / 157
There will be times that we add a three digit number and a 1 or 2 digit number.
5 4 7 + 7 3 =
6 3 9 + 8 =
We follow the same steps!
Regrouping
Slide 57 / 157
5 4 7+ 7 3
If there is no digit, imagine there is a
0.
1 ~ Add the ones2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens4 ~ If it's ten or more, bring the tens next door
5 ~ Add the hundreds
0
Regrouping
Slide 58 / 157
6 3 9+ 8
If there is no digit, imagine there is a
0.
1 ~ Add the ones2 ~ If it's ten or more, bring the tens next door
3 ~ Add the tens4 ~ If it's ten or more, bring the tens next door
5 ~ Add the hundreds
0 0
Regrouping
Slide 59 / 157
7 2 8+ 1 9
Practice
Slide 60 / 157
7 2 8+ 1 9
Add With a Friend
Slide 60 (Answer) / 157
7 2 8+ 1 9
Add With a Friend
[This object is a pull tab]
Teac
her N
otes
Students will need scrap paper or their white boards for the next few slides.
Have students sit with a partner. Have one partner copy the problem onto their
paper. Then the same partner will complete the problem but have them talk out each step they do. You may
want to tell them that they are pretending to be the teacher and explain how to add to their partner. Then switch roles for the next problem. This will help
them gain a better understanding of each step.
Slide 61 / 157
9 5 7+ 5
Add With a Friend
Slide 61 (Answer) / 157
9 5 7+ 5
Add With a Friend
[This object is a pull tab]
Teac
her N
otes
Students will need scrap paper or their white boards for the next few slides.
Have students sit with a partner. Have one partner copy the problem onto their
paper. Then the same partner will complete the problem but have them talk out each step they do. You may
want to tell them that they are pretending to be the teacher and explain how to add to their partner. Then switch roles for the next problem. This will help
them gain a better understanding of each step.
Slide 62 / 157
3 0 7+ 6 7 9
Add With a Friend
Slide 62 (Answer) / 157
3 0 7+ 6 7 9
Add With a Friend
[This object is a pull tab]
Teac
her N
otes
Students will need scrap paper or their white boards for the next few slides.
Have students sit with a partner. Have one partner copy the problem onto their
paper. Then the same partner will complete the problem but have them talk out each step they do. You may
want to tell them that they are pretending to be the teacher and explain how to add to their partner. Then switch roles for the next problem. This will help
them gain a better understanding of each step.
Slide 63 / 157
8 6 7+ 4 2
Add With a Friend
Slide 63 (Answer) / 157
8 6 7+ 4 2
Add With a Friend
[This object is a pull tab]
Teac
her N
otes
Students will need scrap paper or their white boards for the next few slides.
Have students sit with a partner. Have one partner copy the problem onto their
paper. Then the same partner will complete the problem but have them talk out each step they do. You may
want to tell them that they are pretending to be the teacher and explain how to add to their partner. Then switch roles for the next problem. This will help
them gain a better understanding of each step.
Slide 64 / 157
Line them up and add
634 + 126 =
Slide 65 / 157
Line them up and add
238 + 592 =
Slide 66 / 157
Line them up and add
195 + 645 =
Slide 67 / 157
15 Add
8 2 6
+ 7 4
Slide 67 (Answer) / 157
15 Add
8 2 6
+ 7 4
[This object is a pull tab]
Ans
wer
900
Slide 68 / 157
16 Add
4 0 2
+ 3 8
Slide 68 (Answer) / 157
16 Add
4 0 2
+ 3 8
[This object is a pull tab]
Ans
wer
440
Slide 69 / 157
17 Add
4 9
+ 2 7 1
A 220
B 310
C 320
Slide 69 (Answer) / 157
17 Add
4 9
+ 2 7 1
A 220
B 310
C 320 [This object is a pull tab]
Ans
wer
C
Slide 70 / 157
18 Add
4 9 8
+ 9
A 417
B 507
C 517
Quiz
Slide 70 (Answer) / 157
18 Add
4 9 8
+ 9
A 417
B 507
C 517
Quiz
[This object is a pull tab]
Ans
wer
B
Slide 71 / 157
Lab: 1000 Wins
Students will play this card game with a partner to help reinforce adding three digit numbers.
Click here for complete directions
Click to return to Table of Contents
Slide 72 / 157
Slide 73 / 157
Slide 75 / 157
Just like in addition, it is VERY important to line the numbers up on top of each other when subtracting.
One
s
7 8 42 5 2-
Tens
Hun
dred
s
The ones must be lined up, the tens must be lined up and the hundreds must be lined
up.
784 - 252
7 8 4- 2 5 2
Three Digit Subtraction
Slide 76 / 157
Once the problem is lined up correctly, subtract the ones column first.
One
s
7 8 42 5 2-Te
ns
Hun
dred
s
Three Digit Subtraction
Slide 77 / 157
Next, subtract the tens.
One
s
7 8 42 5 2-Te
ns
Hun
dred
s
2
Three Digit Subtraction
Slide 78 / 157
Last, subtract the hundreds.
One
s
7 8 42 5 2-Te
ns
Hun
dred
s
3 2
Three Digit Subtraction
Slide 79 / 157
Rewrite the problem and subtract
354 - 213 =
Three Digit Subtraction
Slide 79 (Answer) / 157
Rewrite the problem and subtract
354 - 213 =
Three Digit Subtraction
[This object is a pull tab]
Teac
her N
otes
For the next few problems, have students rewrite the
problems on a piece of paper at their seats or on individual
white boards. Make sure they are lining up the place
values.
Slide 80 / 157
Rewrite the problem and subtract
400 - 100 =
Three Digit Subtraction
Slide 80 (Answer) / 157
Rewrite the problem and subtract
400 - 100 =
Three Digit Subtraction
[This object is a pull tab]
Teac
her N
otes Use this problem to discuss
subtracting 0 - 0. Remind them that they still have to
write 0 as the answer.
Slide 81 / 157
Rewrite the problem, subtract & explain
579 - 468 =
Three Digit Subtraction
Slide 81 (Answer) / 157
Rewrite the problem, subtract & explain
579 - 468 =
Three Digit Subtraction
[This object is a pull tab]
Mat
h Pr
actic
e
MP.6 Attend to Precision
After students solve the problem, have them explain to a friend how they solved
it.
Slide 82 / 157
Slide 83 / 157
3 4 2 - 1 0 0 =
Remember, just take away 1 from the hundreds!
Three Digit Subtraction
Slide 84 / 157
Subtract
462 - 100 = _____
957 - 100 = _____
690 - 100 = _____
237 - 100 = _____
871 - 100 = _____
Slide 85 / 157
19 Is this problem lined up correctly?
5 3 2
- 2 0
Yes
No
Slide 85 (Answer) / 157
19 Is this problem lined up correctly?
5 3 2
- 2 0
Yes
No
[This object is a pull tab]
Ans
wer
No
Slide 86 / 157
20 When subtracting three digits from three digits, start with the hundreds.
True
False
Slide 86 (Answer) / 157
20 When subtracting three digits from three digits, start with the hundreds.
True
False
[This object is a pull tab]
Ans
wer
False
Slide 87 / 157
21 Subtract
4 0 6
- 1 0 0
A 206
B 506
C 306
Slide 87 (Answer) / 157
21 Subtract
4 0 6
- 1 0 0
A 206
B 506
C 306
[This object is a pull tab]
Ans
wer
C
Slide 88 / 157
22 Subtract
5 7 8
- 2 3 4
A 344
B 744
C 334
Slide 88 (Answer) / 157
22 Subtract
5 7 8
- 2 3 4
A 344
B 744
C 334 [This object is a pull tab]
Ans
wer
A
Slide 89 / 157
23 Subtract
784 - 100 =
Slide 89 (Answer) / 157
23 Subtract
784 - 100 =
[This object is a pull tab]
Ans
wer
684
Slide 90 / 157
Slide 91 / 157
Slide 92 / 157
Subtraction with Borrowing from the Tens
Click to return to Table of Contents
Slide 93 / 157
Regroup means to take apart a number to write it in a new way. We can regroup 14 to 1 ten and 4 ones.
We can regroup 28 to 1 ten and 18 ones.Regroup
Slide 93 (Answer) / 157
Regroup means to take apart a number to write it in a new way. We can regroup 14 to 1 ten and 4 ones.
We can regroup 28 to 1 ten and 18 ones.Regroup
[This object is a pull tab]
Teac
her N
otes
What does regroup mean? Ask students when they have heard this word before. Ask for some
students to explain what it means. Ask if anyone knows why we may need to regroup
when subtracting. Click on the word to show the definition.
Slide 94 / 157
6 8 1- 4 5 2
Start with the ones and subtract
Can we take 2 away from 1? Try it on your fingers. Put up 1 finger, now put two fingers down.
Since 1 is smaller than 2 we cannot complete the problem. What could we do?
Borrowing
Slide 95 / 157
6 8 1- 4 5 2
We can borrow from the tens!If we borrow one ten, how many tens are left?
Cross out the 8 and show the new number.
7 6 8 1- 4 5 2
Borrowing
Slide 96 / 157
6 8 1- 4 5 2
But...Where did the ten that we borrowed go?
71
There it is!
6 8 1- 4 5 2
7
Borrowing
Slide 96 (Answer) / 157
6 8 1- 4 5 2
But...Where did the ten that we borrowed go?
71
There it is!
6 8 1- 4 5 2
7
Borrowing
[This object is a pull tab]
Teac
her N
otes
Click on the problem to show the same problem with the borrowed ten
written next to the ones. Discuss how we write the borrowed amount
next to the number.
Slide 97 / 157
Now just subtract the ones, then the tens and last the hundreds.
6 8 1- 4 5 2
17
When we subtract the tens, will we subtract 8-5 or 7-5? Why?
Borrowing
Slide 98 / 157
5 6 8- 4 2 9
To help you remember when to borrow, think of this rhyme...If more on the floor, borrow from next door.
Do we need to borrow?
Borrowing
Slide 98 (Answer) / 157
5 6 8- 4 2 9
To help you remember when to borrow, think of this rhyme...If more on the floor, borrow from next door.
Do we need to borrow?
Borrowing
[This object is a pull tab]
Teac
her N
otes As you work through this
problem, talk out each step as you do it. Have students
copy the problem at their seats and do it with you.
Slide 99 / 157
9 3 1- 3 1 4
Remember...If more on the floor, borrow from next door.
Do we need to borrow?
Borrowing
Slide 99 (Answer) / 157
9 3 1- 3 1 4
Remember...If more on the floor, borrow from next door.
Do we need to borrow?
Borrowing
[This object is a pull tab]
Teac
her N
otes
As you work through this problem, write the 1 in the ones but "forget" to cross out the 3 and write 2 in the tens. Allow
students the chance to discover your mistake and take the
opportunity to discuss how you got the wrong answer because
of your "mistake".
Slide 100 / 157
2 9 4- 1 5 7
Practice
Slide 100 (Answer) / 157
2 9 4- 1 5 7
Practice
[This object is a pull tab]
Teac
her N
otes
Have students copy the problem and complete it at their seat. Have a student come to
the board and talk out the problem as they solve it.
Slide 101 / 157
5 4 6- 2 9
Practice
What number is here?
Slide 101 (Answer) / 157
5 4 6- 2 9
Practice
What number is here?
[This object is a pull tab]
Teac
her N
otes
Have students copy the problem and complete it at their seat. Have a student come to
the board and talk out the problem as they solve it.
Slide 102 / 157
9 2 4- 8
Practice
What number is here?
Slide 102 (Answer) / 157
9 2 4- 8
Practice
What number is here?
[This object is a pull tab]
Teac
her N
otes
Have students copy the problem and complete it at their seat. Have a student come to
the board and talk out the problem as they solve it.
Slide 103 / 157
24 If there is a larger digit on the bottom, the answer is always 0 since we cannot subtract.
True
False
Slide 103 (Answer) / 157
24 If there is a larger digit on the bottom, the answer is always 0 since we cannot subtract.
True
False
[This object is a pull tab]
Ans
wer
False
Slide 104 / 157
25 Do you need to borrow in this problem?
4 3 2
- 1 2 5
Yes
No
Slide 104 (Answer) / 157
25 Do you need to borrow in this problem?
4 3 2
- 1 2 5
Yes
No
[This object is a pull tab]
Ans
wer
Yes
Slide 105 / 157
26 Do you need to borrow in this problem?
5 8 0
- 1 0 0
Yes
No
Slide 105 (Answer) / 157
26 Do you need to borrow in this problem?
5 8 0
- 1 0 0
Yes
No
[This object is a pull tab]
Ans
wer
480
Slide 106 / 157
27 Subtract
8 4 2
- 2 1 8
A 524
B 636
C 624
Slide 106 (Answer) / 157
27 Subtract
8 4 2
- 2 1 8
A 524
B 636
C 624 [This object is a pull tab]
Ans
wer
C
Slide 107 / 157
28 Subtract
2 3 0
- 1 2 7
Slide 107 (Answer) / 157
28 Subtract
2 3 0
- 1 2 7
[This object is a pull tab]
Ans
wer
103
Slide 108 / 157
Slide 109 / 157
Slide 110 / 157
Subtraction with Borrowing from the Tens and
Hundreds
Click to return to Table of Contents
Slide 111 / 157
6 2 8- 4 1 9
Do we need to regroup?
Regrouping
Slide 111 (Answer) / 157
6 2 8- 4 1 9
Do we need to regroup?
Regrouping
[This object is a pull tab]
Teac
her N
otes
Review what regroup means. Have the students discuss
with a partner if they need to regroup and how. Have them subtract at their seats. Then have a student come to the
board and talk out the problem.
Slide 112 / 157
5 4 7- 2 6 4
Sometimes we may need to borrow from the hundreds.
Borrowing
Slide 112 (Answer) / 157
5 4 7- 2 6 4
Sometimes we may need to borrow from the hundreds.
Borrowing
[This object is a pull tab]
Teac
her N
otes
Work through this problem while talking out each step. Ask the
students for assistance, such as where to start, what to do next,
etc. When you go to subtract the tens ask them if you can subtract 6 from 4. Ask what they think you
should do. Proceed to the next page before subtracting the tens.
Slide 113 / 157
5 4 7- 2 6 4
When we borrow from the hundreds, we are taking 1 hundred away.
How many groups of 10 are in 100?
4
3
Borrowing
Slide 114 / 157
There are 10 groups of 10 in 100.Add the 10 tens that we borrowed to the 4 tens
that we already have.How many tens do we have in all?
5 4 7- 2 6 4
41 5 4 7
- 2 6 4
4
3
Borrowing
Slide 114 (Answer) / 157
There are 10 groups of 10 in 100.Add the 10 tens that we borrowed to the 4 tens
that we already have.How many tens do we have in all?
5 4 7- 2 6 4
41 5 4 7
- 2 6 4
4
3
Borrowing
[This object is a pull tab]
Teac
her N
otes Click on the problem to reveal
the problem with the 1 next to the 4. Explain that the new number is the tens is 14.
Finish subtracting the problem.
Slide 115 / 157
Remember...
More of the floor, borrow from next door.
8 6 9- 4 8 7
Borrowing
Slide 115 (Answer) / 157
Remember...
More of the floor, borrow from next door.
8 6 9- 4 8 7
Borrowing
[This object is a pull tab]
Teac
her N
otes Work through the problem
while students help you talk out the problem.
Slide 116 / 157
Sometimes we may need to borrow from the tens and the hundreds.
8 2 4- 2 6 5
Borrowing
Slide 116 (Answer) / 157
Sometimes we may need to borrow from the tens and the hundreds.
8 2 4- 2 6 5
Borrowing
[This object is a pull tab]
Teac
her N
otes
Work through this problem one step at a time. Show the students how to place the 1 borrowed from the hundreds next to the new number they wrote after borrowing from
the tens.
Slide 117 / 157
Remember...
More of the floor, borrow from next door.
5 1 2- 2 3 4
Borrowing
Slide 117 (Answer) / 157
Remember...
More of the floor, borrow from next door.
5 1 2- 2 3 4
Borrowing
[This object is a pull tab]
Teac
her N
otes
Have students copy the problem at their seat and
then work through it. After they are done, have a
student come to the board and model how they
completed it.
Slide 118 / 157
Practice
7 0 2- 5 6 1
Slide 118 (Answer) / 157
Practice
7 0 2- 5 6 1
[This object is a pull tab]
Teac
her N
otes
Have students copy the problem at their seat and
then work through it. After they are done, have a
student come to the board and model how they
completed it.
Slide 119 / 157
Practice
4 2 4- 1 4 7
Slide 119 (Answer) / 157
Practice
4 2 4- 1 4 7
[This object is a pull tab]
Teac
her N
otesHave students copy the
problem at their seat and then work through it. After
they are done, have a student come to the board
and model how they completed it.
Slide 120 / 157
29 If we cannot subtract in the ones, we should borrow from the hundreds.
True
False
Slide 120 (Answer) / 157
29 If we cannot subtract in the ones, we should borrow from the hundreds.
True
False
[This object is a pull tab]
Ans
wer
False
Slide 121 / 157
30 Subtract
3 6 2
- 1 7 9
A 183
B 217
C 541
Slide 121 (Answer) / 157
30 Subtract
3 6 2
- 1 7 9
A 183
B 217
C 541 [This object is a pull tab]
Ans
wer
A
Slide 122 / 157
31 Subtract
7 2 0
- 3 4 7
A 167
B 373
C 473
Slide 122 (Answer) / 157
31 Subtract
7 2 0
- 3 4 7
A 167
B 373
C 473[This object is a pull tab]
Ans
wer
B
Slide 123 / 157
32 Subtract
395
- 99
Slide 123 (Answer) / 157
32 Subtract
395
- 99
[This object is a pull tab]
Ans
wer
296
Slide 124 / 157
33 Subtract
6 9 3
- 1 2 9
Slide 124 (Answer) / 157
33 Subtract
6 9 3
- 1 2 9
[This object is a pull tab]
Ans
wer
564
Slide 125 / 157
Slide 126 / 157
Slide 128 / 157
7 0 4
- 3 4 6
What should we do if we cannot subtract the ones and there is a 0 in the tens place?
Subtraction Across Zeros
Slide 128 (Answer) / 157
7 0 4
- 3 4 6
What should we do if we cannot subtract the ones and there is a 0 in the tens place?
Subtraction Across Zeros
[This object is a pull tab]
Teac
her N
otes
Allow students to suggest possible ways to solve the
problem. Do not tell them the correct way. Accept all
reasonable ideas. After all ideas are given, advance to
the next slide.
Slide 129 / 157
7 0 4
- 3 4 6
Follow these steps if we cannot subtract the ones and there is a 0 in the tens place:
- draw a box around the hundreds and tens
Subtraction Across Zeros
Slide 130 / 157
7 0 4
- 3 4 6
Follow these steps if we cannot subtract the ones and there is a 0 in the tens place:
- draw a box around the hundreds and tens
- Cross out the number in the box and subtract 1
- Write the new number above
6 9
Subtraction Across Zeros
Slide 131 / 157
7 0 4
- 3 4 6
Follow these steps if we cannot subtract the ones and there is a 0 in the tens place:
- draw a box around the hundreds and tens
- Cross out the number in the box and subtract 1
- Write the new number above
- Write the 1 you took away in the ones
6 91
Subtraction Across Zeros
Slide 132 / 157
7 0 4
- 3 4 6
6 91
Follow these steps if we cannot subtract the ones and there is a 0 in the tens place:
- draw a box around the hundreds and tens
- Cross out the number in the box and subtract 1
- Write the new number above
- Write the 1 you took away in the ones
- Subtract one place at a time starting with the ones
Subtraction Across Zeros
Slide 133 / 157
5 0 2- 3 8 4
Let's Try it Together
Put a box around the hundreds and tensStep 1
Take away one and write the number aboveStep 2
Bring the 1 you borrowed to the ones
SubtractStep 4
Step 3
Slide 133 (Answer) / 157
5 0 2- 3 8 4
Let's Try it Together
Put a box around the hundreds and tensStep 1
Take away one and write the number aboveStep 2
Bring the 1 you borrowed to the ones
SubtractStep 4
Step 3
[This object is a pull tab]
Teac
her N
otes
Click on each "step" to show the explanation.
Work through the problem asking the students what to do each step before
clicking to show the answer. Remember to talk aloud as you do each step
as well.
Slide 134 / 157
3 0 1 - 2 1 9
Let's Try it Together
Put a box around the hundreds and tensStep 1
Take away one and write the number aboveStep 2
Bring the 1 you borrowed to the ones
SubtractStep 4
Step 3
Slide 134 (Answer) / 157
3 0 1 - 2 1 9
Let's Try it Together
Put a box around the hundreds and tensStep 1
Take away one and write the number aboveStep 2
Bring the 1 you borrowed to the ones
SubtractStep 4
Step 3
[This object is a pull tab]
Teac
her N
otes
Click on each "step" to show the explanation.
Work through the problem asking the students what to do each step before
clicking to show the answer. Remember to talk aloud as you do each step
as well.
Slide 135 / 157
8 0 5 - 7 0 6
Subtract
Slide 135 (Answer) / 157
8 0 5 - 7 0 6
Subtract
[This object is a pull tab]
Teac
her N
otes Have students copy the
problem at their seat and solve. Have one student model their work at the
board.
Slide 136 / 157
3 0 1 - 2 1 9
Subtract
Slide 136 (Answer) / 157
3 0 1 - 2 1 9
Subtract
[This object is a pull tab]
Teac
her N
otes Have students copy the problem at their seat and solve. Have one student model their work at the
board.
Slide 137 / 157
8 0 0 - 4 7 2
Subtract
Slide 137 (Answer) / 157
8 0 0 - 4 7 2
Subtract
[This object is a pull tab]
Teac
her N
otes Have students copy the
problem at their seat and solve. Have one student model their work at the
board.
Slide 138 / 157
34 If we cannot subtract the ones and there is a 0 in the tens, can we still complete the problem?
Yes
No
Slide 138 (Answer) / 157
34 If we cannot subtract the ones and there is a 0 in the tens, can we still complete the problem?
Yes
No
[This object is a pull tab]
Ans
wer
Yes
Slide 139 / 157
35 Subtract
7 0 8
- 5 2 9
A 179
B 221
C 279
Slide 139 (Answer) / 157
35 Subtract
7 0 8
- 5 2 9
A 179
B 221
C 279 [This object is a pull tab]
Ans
wer
A
Slide 140 / 157
36 Subtract
5 0 2
- 2 7 5
A 239
B 227
C 128
Slide 140 (Answer) / 157
36 Subtract
5 0 2
- 2 7 5
A 239
B 227
C 128[This object is a pull tab]
Ans
wer
B
Slide 141 / 157
37 Subtract
2 0 5
- 7 9
Slide 141 (Answer) / 157
37 Subtract
2 0 5
- 7 9
[This object is a pull tab]
Ans
wer
126
Slide 142 / 157
38 Subtract
3 0 1
- 1 2 5
Quiz
Slide 142 (Answer) / 157
38 Subtract
3 0 1
- 1 2 5
Quiz
[This object is a pull tab]
Ans
wer
176
Slide 143 / 157
Slide 144 / 157
Slide 145 / 157
Addition and Subtraction Word Problems
Click to return to Table of Contents
Slide 146 / 157
There are 134 apples on one tree. Another tree has 142 apples. How many apples are there in
all?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
Slide 146 (Answer) / 157
There are 134 apples on one tree. Another tree has 142 apples. How many apples are there in
all?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
[This object is a pull tab]
Teac
her N
otes
Discuss with the students how to set up the
equation for this problem. Then model writing the
addition sentence on the board and finally add.
Slide 147 / 157
A store has 264 dolls. They sold 127. How many dolls do they have left?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
Slide 147 (Answer) / 157
A store has 264 dolls. They sold 127. How many dolls do they have left?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
[This object is a pull tab]
Mat
h Pr
actic
e
MP4 - Model with Mathematics
The word problem is a real world situation that students need to use math to solve.
Have students write a subtraction sentence to represent the problem.
Slide 148 / 157
312 boys are at the football game. 389 girls are at the football game. How kids are at the game
in all?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
Slide 148 (Answer) / 157
312 boys are at the football game. 389 girls are at the football game. How kids are at the game
in all?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
[This object is a pull tab]
Teac
her N
otes
Discuss with the students how to set up the
equation for this problem. Then model writing the
addition sentence on the board and finally add.
Slide 149 / 157
Kathy saw 174 ants on her deck. 89 crawl away. How many ants are left?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
Slide 149 (Answer) / 157
Kathy saw 174 ants on her deck. 89 crawl away. How many ants are left?
What information do we have to help to help us solve this problem?
Are we adding or subtracting?
Word Problems
[This object is a pull tab]
Teac
her N
otes
Discuss with the students how to set up the
equation for this problem. Then model writing the subtraction sentence on
the board and finally subtract.
Slide 150 / 157
Story Time
Work with a friend to use the two numbers below to make up your own addition or subtraction story. Then
solve the problem.
568 264
Slide 150 (Answer) / 157
Story Time
Work with a friend to use the two numbers below to make up your own addition or subtraction story. Then
solve the problem.
568 264[This object is a pull tab]
Teac
her N
otes
Assign students are partner to work with. Each group with
need a piece of paper to write their stories on. Have two different groups share their stories to be solved on the
board. Give the students a few more opportunities to make up their own stories with a partner.
Slide 151 / 157
39 Pick the two numbers that you will add together for this problem.
234 fish are in the pond. 341 new fish are added. How many fish are in the pond now?
A 341
B 575
C 234
Slide 151 (Answer) / 157
39 Pick the two numbers that you will add together for this problem.
234 fish are in the pond. 341 new fish are added. How many fish are in the pond now?
A 341
B 575
C 234
[This object is a pull tab]
Ans
wer
C & A
Slide 152 / 157
40 Jim's family is driving to Disney World. It is 672 miles from thier house. They drove 341 miles the first day. How many miles do they still need to drive?
A 1013
B 231
C 331
Slide 152 (Answer) / 157
40 Jim's family is driving to Disney World. It is 672 miles from thier house. They drove 341 miles the first day. How many miles do they still need to drive?
A 1013
B 231
C 331
[This object is a pull tab]
Ans
wer
C
Slide 153 / 157
41 Kim baked 215 cookies for Christmas. Her sister cooked 100 more than her. How many cookies did her sister bake?
Slide 153 (Answer) / 157
41 Kim baked 215 cookies for Christmas. Her sister cooked 100 more than her. How many cookies did her sister bake?
[This object is a pull tab]
Ans
wer
315
Slide 154 / 157
42 Nick saw 345 birds on the wire. 100 of them flew away. How many birds are left?
Slide 154 (Answer) / 157
42 Nick saw 345 birds on the wire. 100 of them flew away. How many birds are left?
[This object is a pull tab]
Ans
wer
245
Slide 155 / 157
43 The farmer picked 252 blueberries. His son picked 459 more than him. How many did his son pick?
Quiz
Slide 155 (Answer) / 157
43 The farmer picked 252 blueberries. His son picked 459 more than him. How many did his son pick?
Quiz
[This object is a pull tab]
Ans
wer
711
Slide 156 / 157
Slide 157 / 157