Estimating Square Roots and Division Worksheet
How to do it in your head (Guess, divide, average): Division: round the divisor to the nearest ten and find the closest multiple of it. Square root: guess the nearest whole root, then divide the number by your guess. Average the guess and the answer of the division, and round to 1 decimal place.
NameDateTime takenScore ___ / 40
- 1.Best estimate of 7626 ÷ 82? (a) 950 (b) 9500 (c) 95
- 2.√94 to 1 decimal place? (a) 9.8 (b) 9.9 (c) 9.7 (d) 10.0
- 3.Best estimate of 1938 ÷ 43? (a) 48 (b) 4800 (c) 480
- 4.Best estimate of 1868 ÷ 52? (a) 37 (b) 370 (c) 3700
- 5.Best estimate of 1239 ÷ 34? (a) 410 (b) 4100 (c) 41
- 6.√37 to 1 decimal place? (a) 6.0 (b) 5.9 (c) 6.1 (d) 6.2
- 7.√77 to 1 decimal place? (a) 8.7 (b) 8.6 (c) 8.9 (d) 8.8
- 8.Best estimate of 2633 ÷ 33? (a) 88 (b) 8800 (c) 880
- 9.√96 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.5
- 10.Best estimate of 1065 ÷ 39? (a) 27 (b) 2700 (c) 270
- 11.√47 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.7 (d) 6.8
- 12.Best estimate of 1607 ÷ 48? (a) 3200 (b) 32 (c) 320
- 13.Best estimate of 3829 ÷ 87? (a) 43 (b) 4300 (c) 430
- 14.Best estimate of 1555 ÷ 66? (a) 2200 (b) 220 (c) 22
- 15.Best estimate of 4145 ÷ 66? (a) 59 (b) 590 (c) 5900
- 16.√72 to 1 decimal place? (a) 8.3 (b) 8.4 (c) 8.5 (d) 8.2
- 17.√46 to 1 decimal place? (a) 6.9 (b) 7.1 (c) 6.8 (d) 7.0
- 18.Best estimate of 7536 ÷ 79? (a) 94 (b) 940 (c) 9400
- 19.Best estimate of 3243 ÷ 87? (a) 3600 (b) 360 (c) 36
- 20.√45 to 1 decimal place? (a) 6.8 (b) 6.6 (c) 6.5 (d) 6.7
- 21.Best estimate of 1693 ÷ 26? (a) 56 (b) 5600 (c) 560
- 22.Best estimate of 2197 ÷ 33? (a) 730 (b) 7300 (c) 73
- 23.Best estimate of 2605 ÷ 86? (a) 290 (b) 2900 (c) 29
- 24.√21 to 1 decimal place? (a) 4.9 (b) 4.7 (c) 4.8 (d) 4.6
- 25.√22 to 1 decimal place? (a) 4.7 (b) 4.9 (c) 4.8 (d) 4.6
- 26.Best estimate of 4562 ÷ 57? (a) 760 (b) 7600 (c) 76
- 27.√90 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.7 (d) 9.8
- 28.Best estimate of 2067 ÷ 34? (a) 69 (b) 6900 (c) 690
- 29.Best estimate of 1283 ÷ 83? (a) 1600 (b) 16 (c) 160
- 30.Best estimate of 1976 ÷ 36? (a) 49 (b) 490 (c) 4900
- 31.Best estimate of 6073 ÷ 64? (a) 10100 (b) 1010 (c) 101
- 32.√26 to 1 decimal place? (a) 5.3 (b) 5.2 (c) 5.1 (d) 5.4
- 33.Best estimate of 4474 ÷ 86? (a) 500 (b) 50 (c) 5000
- 34.Best estimate of 1300 ÷ 48? (a) 2600 (b) 26 (c) 260
- 35.Best estimate of 1280 ÷ 36? (a) 3200 (b) 320 (c) 32
- 36.√24 to 1 decimal place? (a) 4.9 (b) 5.0 (c) 4.7 (d) 4.8
- 37.Best estimate of 3739 ÷ 56? (a) 6200 (b) 62 (c) 620
- 38.Best estimate of 3240 ÷ 56? (a) 540 (b) 5400 (c) 54
- 39.Best estimate of 583 ÷ 27? (a) 1900 (b) 190 (c) 19
- 40.Best estimate of 3186 ÷ 38? (a) 8000 (b) 800 (c) 80
Answer key
- 95
- 9.7
- 48
- 37
- 41
- 6.1
- 8.8
- 88
- 9.8
- 27
- 6.9
- 32
- 43
- 22
- 59
- 8.5
- 6.8
- 94
- 36
- 6.7
- 56
- 73
- 29
- 4.6
- 4.7
- 76
- 9.5
- 69
- 16
- 49
- 101
- 5.1
- 50
- 26
- 32
- 4.9
- 62
- 54
- 19
- 80
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