Rounding
Estimating sums
Estimating Differences
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
Estimate the difference 546 - 324
500 - 300 = 200
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
Estimate the difference 3,756 - 3,421
4,000 - 3,000 = 1,000
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 sum 127,998 + 456, 876
100,000 + 500,000 = 600,000
300
Estimate the difference $567 - $432
$600 - $400 = $200
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 sum 3,956 + 4,956
4,000 + 5,000 = 9,000
400
Estimate the difference $6,789 - $2,987
$7,000 - $3,000 = $4,000
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
Estimate the difference $7,896 - $5,984
$8,000 - $6,000 = $2,000
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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