# Estimate Sums and Differences

Contributed by:
In this pdf, you will learn to estimate sums and differences using the method of rounding the number to the leading digit.
1. Estimating sums and differences ✩
Round the numbers to the leading digit. Estimate the sum or difference.
3,576 → 4,000 198,248 → 200,000
+ 1,307 → +1,000 – 116,431 → –1,00,000
Round the numbers to the leading digit. Estimate the sum or difference.
685 → 21,481 → 7,834 →
+ 489 → – 12,500 → + 3,106 →
682,778 → 58,499 → 902,276 →
+ 130,001 → – 22,135 → – 615,999 →
46,801 → 9,734 → 65,606 →
+ 34,700 → – 8,306 → + 85,943 →
5,218 → 745 → 337,297 →
– 3,673 → + 451 → – 168,931 →
Write < or > for each problem.
329 + 495 800 11,569 – 6,146 6,000
563 – 317 300 8,193 – 6,668 1,000
41,924 – 12,445 50,000 634,577 + 192,556 800,000
18,885 + 12,691 30,000 713,096 – 321,667 400,000
2. 8 4 0 2 8 4
2
6
3
1
3
4
0
1
9
Estimating sums and differences ✩ 1
7 1
2
3
Round the numbers to the leading digit. Estimate the sum or difference. 2 4
5
6
3,576 → 4,000 198,248 → 200,000
0
7
+ 1,307 → + 1,000 – 116,431 → – 100,000 8
7 10
11
Round the numbers to the leading digit. Estimate the sum or difference. 6 12
13
14
685 → 700 21,481 → 20,000 7,834 → 8,000 15
8
+ 489 → + 500 – 12,500 → – 10,000 + 3,106 → + 3,000 16
18
19
682,778 → 700,000
+ 130,001 → + 100,000
58,499 → 60,000
– 22,135 → – 20,000
902,276 → 900,000
– 615,999 → – 600,000
1 20
21
3
23
24
46,801 → 50,000 9,734 → 10,000 65,606 → 70,000
9 25
+ 34,700 → + 30,000 – 8,306 → – 8,000 + 85,943 → + 90,000
5 26
27
28
29
5,218 →
– 3,673 →
5,000
– 4,000
745 →
+ 451 →
700
+ 500
337,297 → 300,000
– 168,931 → – 200,000
4 30
31
32
9 33
34
35
2
Write < or > for each problem. 36
37
329 + 495 > 800 11,569 – 6,146 < 6,000 3 38
39
40
563 – 317 < 300 8,193 – 6,668 > 1,000
41
41,924 – 12,445 < 50,000 634,577 + 192,556 > 800,000
5 42
43
6
44
45
46
18,885 + 12,691 > 30,000 713,096 – 321,667 < 400,000
47
9 48
2 7 2
115
7
8
3
6 carefully if the
9
In section 2, children need to think about their estimates more
0
4
3
estimate is very close to the number on the right side of the equation. Have
them look at the numbers in the next place to the right to adjust their estimates
up or down.