Vocabulary
What is rounding?
27 rounded to the nearest 10.
What is 30?
76+89=
What is 165?
88-29=
What is 59?
Ms. Bates baked 213 cookies on Friday. On Saturday she baked 187 cookies. How many more cookies did she bake on Friday than on Saturday?
What are 26 more cookies on Friday?
The answer in an addition problem.
What is the sum?
124 rounded to the nearest 10.
What is 120?
127+183=
What is 310?
960-686=?
What is 274?
Najat says that 367 + 429 is about 1,000. Do you agree or disagree?
I disagree because the sum is closer to 800.
The answer in a subtraction problem.
What is the difference?
387 rounded to the nearest 100.
What is 400?
Write an equation to estimate this problem: 198+387.
What is 200+390=590?
OR
What is 200+400=600?
Write an equation to estimate this problem: 683-221.
What is 680-220=460?
OR
What is 700-200=500
Which two numbers have a sum closest to 1,000?
327 482 600 398
What are 600 and 398?
Using rounding to determine if a sum or difference is reasonable.
What is estimating?
959 rounded to the nearest 100.
What is 1,000?
127+320=125+____
What is 322?
675 - 48 = ___ - 50
What is 677?
Use estimation to solve. Do not find the exact answer.
Shawna has a photo album with space for 160 pictures. She has 33 family pictures, 48 camp pictures, and 57 school pictures. Does she have enough pictures to fill the whole album?
What is no?
30+50=80
80+60=140
Making an easier subtraction problem by shifting both amounts equally.
What is constant difference?
2,478 rounded to the nearest 10.
What is 2,480?
True or false:
354+296 = 358+300
What is false?
True or false:
729 - 270 = 727 - 268
What is true?
Write an equation to represent this problem. Then solve.
Yusuf and Khadro collect cans to recycle. Yusuf has 275 cans and Khadro has 168 cans. On their way to the recycling center, their bag breaks and 89 cans fall out. How many cans do they have now?
(275+168) - 89 = c
What are 354 cans?