Rounding
Estimating
Word Problems
Exact sums and differences
Subtract Across Zeros
100
Round to the nearest ten thousand 12,345
12,000
100
Estimate the sum. 356 + 487
400 + 500 = 900
100

John scores 247 points in a video games.  How many more points does he need to score a total of 650 points?

What is 403 points

100
345 + 456 =
345 + 456 = 801
100
5,000 - 2,345 =
5,000 - 2,345 = 2,655
200
Round to the nearest hundred thousand. 546,457
500,000
200
Estimate the sum 5,478 + 8,567
5,000 + 9,000 = 14,000
200

An airplane flies 659 miles in the morning and then flies 356 miles in the afternoon.  How many miles did the airplane fly in total?

659 + 356 = 1015 miles

200
6,578 - 3,456 =
6,578 - 3,456 = 3,122
200
3,000 - 2,395 =
3,000 - 2,395 = 605
300
Round to the highest place value. 5,654,890
6,000,000
300

Estimate the difference 546 - 324

500 - 300 = 200

300

On Saturday 453 people go to a school play.  On Sunday 294 people go to the play.  How many more people go to the play on Saturday?

453 - 294 = 159 people

300
23,567 + 56,879 =
23,567 + 56,879 = 80,446
300
9,000 - 4,587 =
9,000 - 4,587 = 4,413
400
Round to the nearest ten thousand. 189,564
190,000
400

Estimate the difference $567 - $432

$600 - $400 = $200

400

In one week, 128 cell phones were sold.  The following week 37 more cellphones were sold than the week before.  How many cell phones were sold in those two weeks?

128 week 1

128 + 37 = 165 Week 2

128 + 165 = 293 Cell phones

400
7,065 - 5,406 =
7,065 - 5,406 = 1,659
400
50,000 - 34,876 =
50,000 - 34,876 = 15,124
500
Round to the nearest hundred thousand. 956,390
1,000,000
500
Estimate the sum 123,987 + 34,987
100,000 + 30,000 =130,000
500

Mrs. Oestreich picked 146 tomatoes from her garden on Friday.  On Saturday, I picked 17 more tomatoes than on Friday.  How tomatoes did I pick in all? 

Friday. 146


Saturday 146 + 17  =  163


146 + 163 = 309 Tomatoes


500
6,504 - 3,297 =
6,504 - 3,297 = 3,207
500
300,000 - 234, 564 =
300,000 - 234, 564 = 65,436
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