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.√67 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 8.1 (d) 8.3
- 2.Best estimate of 2341 ÷ 44? (a) 590 (b) 5900 (c) 59
- 3.√88 to 1 decimal place? (a) 9.6 (b) 9.3 (c) 9.4 (d) 9.5
- 4.Best estimate of 3466 ÷ 41? (a) 8700 (b) 870 (c) 87
- 5.Best estimate of 2112 ÷ 26? (a) 700 (b) 7000 (c) 70
- 6.√58 to 1 decimal place? (a) 7.7 (b) 7.4 (c) 7.6 (d) 7.5
- 7.√37 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 5.9 (d) 5.8
- 8.Best estimate of 2195 ÷ 43? (a) 55 (b) 550 (c) 5500
- 9.Best estimate of 1721 ÷ 29? (a) 57 (b) 570 (c) 5700
- 10.Best estimate of 3547 ÷ 57? (a) 5900 (b) 590 (c) 59
- 11.√74 to 1 decimal place? (a) 8.4 (b) 8.6 (c) 8.5 (d) 8.7
- 12.√48 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 6.9 (d) 7.0
- 13.√42 to 1 decimal place? (a) 6.5 (b) 6.7 (c) 6.4 (d) 6.6
- 14.√31 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.5 (d) 5.6
- 15.Best estimate of 4069 ÷ 43? (a) 1020 (b) 10200 (c) 102
- 16.Best estimate of 1795 ÷ 41? (a) 4500 (b) 450 (c) 45
- 17.Best estimate of 1186 ÷ 42? (a) 3000 (b) 300 (c) 30
- 18.Best estimate of 6601 ÷ 87? (a) 73 (b) 7300 (c) 730
- 19.√94 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.5
- 20.√98 to 1 decimal place? (a) 9.7 (b) 9.9 (c) 9.8 (d) 9.6
- 21.Best estimate of 6876 ÷ 76? (a) 860 (b) 86 (c) 8600
- 22.Best estimate of 1888 ÷ 42? (a) 4700 (b) 470 (c) 47
- 23.Best estimate of 1692 ÷ 28? (a) 5600 (b) 560 (c) 56
- 24.Best estimate of 3455 ÷ 52? (a) 6900 (b) 69 (c) 690
- 25.Best estimate of 2808 ÷ 32? (a) 94 (b) 9400 (c) 940
- 26.√84 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 8.9
- 27.√70 to 1 decimal place? (a) 8.2 (b) 8.5 (c) 8.3 (d) 8.4
- 28.Best estimate of 3303 ÷ 47? (a) 66 (b) 6600 (c) 660
- 29.√59 to 1 decimal place? (a) 7.6 (b) 7.9 (c) 7.8 (d) 7.7
- 30.Best estimate of 1152 ÷ 37? (a) 2900 (b) 29 (c) 290
- 31.√65 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 8.0 (d) 7.8
- 32.√20 to 1 decimal place? (a) 4.4 (b) 4.3 (c) 4.5 (d) 4.2
- 33.√34 to 1 decimal place? (a) 6.0 (b) 5.8 (c) 5.7 (d) 5.9
- 34.√63 to 1 decimal place? (a) 7.7 (b) 7.8 (c) 7.9 (d) 7.6
- 35.Best estimate of 669 ÷ 33? (a) 22 (b) 220 (c) 2200
- 36.√77 to 1 decimal place? (a) 8.5 (b) 8.7 (c) 8.8 (d) 8.6
- 37.Best estimate of 627 ÷ 42? (a) 1600 (b) 16 (c) 160
- 38.Best estimate of 2572 ÷ 39? (a) 6400 (b) 64 (c) 640
- 39.Best estimate of 1081 ÷ 42? (a) 270 (b) 2700 (c) 27
- 40.Best estimate of 7447 ÷ 83? (a) 93 (b) 9300 (c) 930
Answer key
- 8.2
- 59
- 9.4
- 87
- 70
- 7.6
- 6.1
- 55
- 57
- 59
- 8.6
- 6.9
- 6.5
- 5.6
- 102
- 45
- 30
- 73
- 9.7
- 9.9
- 86
- 47
- 56
- 69
- 94
- 9.2
- 8.4
- 66
- 7.7
- 29
- 8.1
- 4.5
- 5.8
- 7.9
- 22
- 8.8
- 16
- 64
- 27
- 93
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