Estimate Sums and Differences
Adding Whole
Numbers
Subtracting Whole Numbers
Subtracting Across Zeros
Mental Math-answer in 20 seconds!
100
542 + 27
What is 570?
100
78 + 421
What is 499?
100
217 - 166
What is 51?
100
600 - 177
What is 423?
100
57 + 0
What is 57?
200
778 + 95
What is 900?
200
873 + 4,893
What is 5j,766?
200
479 - 88
What is 391?
200
4,000 - 1,698
What is 2,302?
200
81 + 21
What is 102?
300
1,724 - 731
What is 1,000?
300
8,496 + 265
What is 8,761?
300
3,711 - 1,683
What is 2,028?
300
5,025 - 178
What is 4,847?
300
200 - 89
What is 111?
400
Estimate by rounding to the nearest ten. Show your problem and your answer! 6, 324 + 3, 842
What is 6,320 + 3,840 = 10, 160
400
7,845 + 509 + 3,746
What is 12,100?
400
8,327 - 3,796
What is 4,531?
400
10,807 - 4,373
What is 6,434?
400
(40 + 6) - 3
What is 43?
500
This year, 35,694 people ran in a marathon. Last year, 8,889 fewer people ran in the marathon. About how many people ran in last year's marathon?
What is about 27, 000 people?
500
There were 10,453 items checked out at the library one week. The next week, there were 12,975 items checked out. The third week, there were 9,634 items checked out. How many items were checked out in three weeks' time?
What is 33, 062
500
A crayon company makes 17, 491 green crayons and 15,063 blue crayons. How may more green crayons are made than blue crayons?
What is 2,428 more green crayons?
500
Kalin scored 10, 830 points on a video game. Karina scored 9,645 points. How many more points did Kalin score than Karina?
What is 1,185 more points?
M
e
n
u