MultiplicationBrought to you by powerpointpros.com

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Lesson MenuWhat is Multiplication?Using MultiplicationPractice with MultiplicationMultiplying Numbers0 and 1Commutative Property of MultiplicationReviewAlso by PowerPoint Pros.com:AdditionSubtraction

What is Multiplication?

Multiplication is the process of combining numbers to obtain their product, or, answer.

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The Multiplication Symbol

To show that you are using multiplication, these two symbols are often used:X•

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How do I use Multiplication?

Let’s take a problem like 3 X 4…

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3 X 4=

What we are really saying in this problem is What is 3 groups of 4? (What is 4+4+4?) To demonstrate this, we’ll use apples…

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“3 Groups of 4 apples (4+4+4)”

This is 1 group of 4 apples.We need 2 more of these groups!

This is the second group! Only 1 more!

We have all 3 groups! How many apples are there altogether? 12 apples

The Answer

So now we know that 3 X 4 is 12! Let’s try another example problem…

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Example 2

What is 5 X 2?

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Writing it as an “Apple Question”

What is 5 groups of 2 apples? (What is 2+2+2+2+2?)

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“5 Groups of 2 Apples (2+2+2+2+2)”

This is 1 group of 2 apples.We need 4 more of these groups!

How many apples do we have?10 apples

The Answer

By demonstrating using apples, we were able to see that 5 X 2=10. Now, why don’t you try some practice on your own?

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1 X 2 (What is 1 group of 2 apples?)

How many apples do we have?2 apples

2 X 3 (What is 2 groups of 3 apples?)

How many apples do we have?6 apples

3 X 1

How many apples do we have?3 apples

Multiplying with Numbers

We can’t always use apples to help us multiply. We need to start learning how to multiply with only numbers, like this…

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4 X 2

We can still write the problem out in the same way that we did before, only without the apples.

What is 4 groups of 2?

And even though the problem isn’t asking for us to work with apples, we can still use apples to model our problem, if we need help.

Modeling with Apples: 4 X 2

How many apples do we have?8 apples

The Answer

Even though we modeled our problem using apples, the question wasn’t “What is 4 groups of 2 apples?” It was, “What is 4 groups of 2?” So, even though we used apples to help us solve the problem, the answer isn’t 8 apples, it’s just 8.

More Practice Multiplying with Numbers

We’ll look at some more problems that we can solve using multiplication. Try and solve the problem before the answers (or even the apples) are shown on the board. Remember to answer with only numbers, not apples!

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Multiplying Numbers: 1 X 5What is 1 group of 5?

How many apples do we have?

5 apples

Try to find the answer before it is shown on the board, or even before the apples are shown on the board! Remember that the answer is in numbers, not apples!

What, then, is the answer to the problem?

(NO APPLES!)5

Multiplying Numbers: 2 X 6What is 2 groups of 6?

How many apples do we have?

12 apples

Try to find the answer before it is shown on the board, or even before the apples are shown on the board! Remember that the answer is in numbers, not apples!

What, then, is the answer to the problem?

(NO APPLES!)

12

Multiplying Numbers: 1 X 1

What is the answer to the problem? 1 NEE

D H

ELP?

Great job!

Eventually, you’ll be able to multiply numbers without even using apples! (But for now, if you need them for help, that’s okay.) Remember that you need to PRACTICE so that you can be a multiplication expert!

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0 and 1

0 and 1 are two special numbers in multiplication. We’ll show you some cool tricks on how to multiply with these numbers.

0 1

0

The rule with a 0 is that every time that you multiply with a 0, the answer is ALWAYS going to be 0.

Let’s try it using apples!

0

3 X 0What is 3 groups of 0?

How many apples do we have?

0 applesWhat, then, is the answer

to the problem?(NO APPLES!)

0

0

That same trick works with any number. 1 X 0 is 0; 2 X 0 is 0; 100 X 0 is 0. It always works!

0

1

1 is another special number in multiplication. The rule with a 1 is that any number times (X) 1 equals that same number.

Let’s try it using apples!

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1 X 3(What is 1 group of 3?)

How many apples do we have?

3 applesWhat, then, is the answer

to the problem?(NO APPLES!)

3

1

Since the problem was 1 X 3, the answer was 3. That trick works with any number multiplied by 1. 4 X 1 is 4; 10 X 1 is 10; 100 X 1 is 100. It always works (as long as you’re only multiplying 1 number by 1!)

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What is the Commutative Property?

The commutative property of multiplication means that you can switch around the numbers in a multiplication problem and still get the same answer. For example…

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1 X 3(What is 1 group of 3?)

How many apples do we have?

3 applesWhat, then, is the answer

to the problem?(NO APPLES!)

3

We know that 1 X 3 is 3. But what if we switch it

around and multiply 3 X 1?

3 X 1(What is 3 groups of 1?)

How many apples do we have?

3 applesWhat, then, is the answer

to the problem?(NO APPLES!)

3

So, if we compare the two problems, we see that they both had the same answer…even though we switched the numbers around!

Practice with the Commutative Property

Let’s try this once more!

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2 X 3(What is 2 groups of 3?)

How many apples do we have?

6 applesWhat, then, is the answer

to the problem?(NO APPLES!)

6

Switch it around to 3 X 2…(What is 3 groups of 2?)

How many apples do we have?

6 applesWhat, then, is the answer

to the problem?(NO APPLES!)

6

So, if we compare the two problems, we see that, again, they both had the same answer…even

though we switched the numbers around! So the commutative property really does work!

Review

Now, we’re going to review all that we have learned!!!

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Review: 1

What is multiplication?Multiplication is the process of combining numbers to obtain their product, or, answer.

What are the two most common multiplication symbols?X and •

Review: 2

What are we saying when we have a problem like 3 X 4?What is 3 groups of 4?, or 4+4+4

What is the answer when we multiply any number by 0?0

By 1?The other number (the one besides 1)

Review: 3

What do we mean when we talk about the Commutative Property of Multiplication?We mean that we can switch the numbers around in a multiplication problem and still get the same product, or answer.

Review: 4

Solve these multiplication problems.1. What is 3 groups of 4?2. 5 X 23. 3 X 04. 3 X 15. 3 X 56. What is 1 group of 1?

121003151

Review: 5

Solve these multiplication problems.1. What is 2 groups of 6?2. 3 X 33. 10 X 14. 3 X 25. 4 X 26. 1,000,000,000,000 X 0

12910680

Review Menu (Any topic you’d like to review?)What is Multiplication?Using MultiplicationPractice with MultiplicationMultiplying Numbers0 and 1Commutative Property of MultiplicationReviewAlso by PowerPoint Pros.com:AdditionSubtraction

Congratulations!

You now know the basics of multiplication! Great job!

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