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.√37 to 1 decimal place? (a) 6.0 (b) 6.3 (c) 6.1 (d) 6.2
- 2.√78 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
- 3.√26 to 1 decimal place? (a) 5.3 (b) 5.2 (c) 5.1 (d) 5.4
- 4.√56 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.7
- 5.√63 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
- 6.Best estimate of 1147 ÷ 44? (a) 290 (b) 2900 (c) 29
- 7.Best estimate of 4119 ÷ 71? (a) 5900 (b) 59 (c) 590
- 8.Best estimate of 2891 ÷ 32? (a) 960 (b) 9600 (c) 96
- 9.Best estimate of 3641 ÷ 39? (a) 91 (b) 9100 (c) 910
- 10.√34 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 6.0 (d) 5.7
- 11.√84 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.4 (d) 9.3
- 12.Best estimate of 4689 ÷ 56? (a) 780 (b) 7800 (c) 78
- 13.Best estimate of 6564 ÷ 83? (a) 8200 (b) 82 (c) 820
- 14.√58 to 1 decimal place? (a) 7.5 (b) 7.7 (c) 7.8 (d) 7.6
- 15.√96 to 1 decimal place? (a) 9.8 (b) 10.1 (c) 9.9 (d) 10.0
- 16.Best estimate of 2111 ÷ 38? (a) 5300 (b) 53 (c) 530
- 17.√61 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
- 18.√40 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.4 (d) 6.5
- 19.Best estimate of 3220 ÷ 62? (a) 540 (b) 54 (c) 5400
- 20.Best estimate of 2029 ÷ 28? (a) 68 (b) 6800 (c) 680
- 21.√43 to 1 decimal place? (a) 6.8 (b) 6.9 (c) 6.6 (d) 6.7
- 22.Best estimate of 1953 ÷ 47? (a) 390 (b) 3900 (c) 39
- 23.Best estimate of 7663 ÷ 82? (a) 96 (b) 9600 (c) 960
- 24.√69 to 1 decimal place? (a) 8.4 (b) 8.1 (c) 8.2 (d) 8.3
- 25.Best estimate of 669 ÷ 31? (a) 22 (b) 2200 (c) 220
- 26.Best estimate of 1307 ÷ 42? (a) 330 (b) 3300 (c) 33
- 27.Best estimate of 2777 ÷ 77? (a) 3500 (b) 350 (c) 35
- 28.Best estimate of 1727 ÷ 62? (a) 290 (b) 2900 (c) 29
- 29.Best estimate of 493 ÷ 32? (a) 160 (b) 1600 (c) 16
- 30.√74 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.8 (d) 8.6
- 31.√41 to 1 decimal place? (a) 6.3 (b) 6.4 (c) 6.5 (d) 6.6
- 32.Best estimate of 2962 ÷ 37? (a) 7400 (b) 740 (c) 74
- 33.√32 to 1 decimal place? (a) 5.5 (b) 5.6 (c) 5.4 (d) 5.7
- 34.Best estimate of 6444 ÷ 68? (a) 92 (b) 9200 (c) 920
- 35.Best estimate of 2836 ÷ 32? (a) 9500 (b) 950 (c) 95
- 36.Best estimate of 4046 ÷ 46? (a) 8100 (b) 81 (c) 810
- 37.√29 to 1 decimal place? (a) 5.4 (b) 5.1 (c) 5.2 (d) 5.3
- 38.Best estimate of 1508 ÷ 32? (a) 500 (b) 50 (c) 5000
- 39.Best estimate of 1684 ÷ 78? (a) 21 (b) 2100 (c) 210
- 40.Best estimate of 1108 ÷ 34? (a) 37 (b) 3700 (c) 370
Answer key
- 6.1
- 8.8
- 5.1
- 7.5
- 7.9
- 29
- 59
- 96
- 91
- 5.8
- 9.2
- 78
- 82
- 7.6
- 9.8
- 53
- 7.8
- 6.3
- 54
- 68
- 6.6
- 39
- 96
- 8.3
- 22
- 33
- 35
- 29
- 16
- 8.6
- 6.4
- 74
- 5.7
- 92
- 95
- 81
- 5.4
- 50
- 21
- 37
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