2. estimating differences
TRANSCRIPT
ESTIMATING DIFFERENCES
4 753
84 387
59 367 38 732
3 575 4 385
547 203
47 259
1 543
Hundreds Thousands
1) 253 2) 3 4373) 125 4) 6 0535) 478 6) 4 8577) 659 8) 8 2109) 304 10) 7 489
Mr. Cruz has 782 square meters of land planted with corn and
575 square meters planted with palay. About how many
square meters more of land were planted with palay than with
corn?
What is asked in the problem?What operation are we going to use?
What will be the number sentence for the problem?
Execute our planAround 200 square meters of land were planted to palay than corn
782 800 -575 -600
Check your work
Exact Difference Estimated Difference
782 800 - 575_ - 600
207 200207 I close to 200
Guided Practice
4 615 - 3 243
536 - 275
8 937 - 4 352
6 836 - 2 595
483 - 124
882 - 416
6 247 - 3 281
7 086 -2 540
748 -334
296 - 154
Remember:
To estimate the difference:
a. Round the minuend and the subtrahend to their greatest place value.
b. Subtract the rounded numbers.
Complete the puzzle boxes by estimating. The answer in the bottom right corner of each box will be the same when subtracting across or down.
1 287 891888 641
Estimate the difference by rounding the numbers to its highest place value then subtract. Write the answer in your notebook.1) 643 2) 846 -448 - 551
3) 558 4) 452 - 99 -125
5) 758 -174
6) 8 435 7) 9 071 - 2 526 - 2 052
8) 4 892 9) 8 465 - 1 261 - 3 259
10) 4 936 - 2 143
Assignment:
Write a good estimate after each problem, then solve.
1. Mr. Reyes wanted to sell 302 tickets for a cultural show. He sold 191 tickets. About how many more tickets should he sell?
Estimate by rounding to the nearest hundredsAnswer:
2. There are 8 936 books in Manuel L. Quezon Elementary School. Manuel Roxas Elementary School has 7 642 books in its library. How many more books does Manuel L. Quezon Elementary School have than Manuel Roxas Elementary School?
Estimate by rounding to the nearest thousands:Answer: