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.√96 to 1 decimal place? (a) 9.7 (b) 9.8 (c) 9.6 (d) 9.9
- 2.Best estimate of 2385 ÷ 34? (a) 8000 (b) 80 (c) 800
- 3.Best estimate of 1188 ÷ 46? (a) 2400 (b) 240 (c) 24
- 4.Best estimate of 3197 ÷ 46? (a) 640 (b) 64 (c) 6400
- 5.√71 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.1 (d) 8.4
- 6.Best estimate of 954 ÷ 21? (a) 480 (b) 48 (c) 4800
- 7.Best estimate of 6488 ÷ 76? (a) 8100 (b) 81 (c) 810
- 8.√62 to 1 decimal place? (a) 7.8 (b) 8.1 (c) 7.9 (d) 8.0
- 9.Best estimate of 2101 ÷ 22? (a) 105 (b) 1050 (c) 10500
- 10.√38 to 1 decimal place? (a) 6.5 (b) 6.2 (c) 6.4 (d) 6.3
- 11.√74 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
- 12.Best estimate of 2209 ÷ 49? (a) 4400 (b) 440 (c) 44
- 13.Best estimate of 1996 ÷ 88? (a) 220 (b) 2200 (c) 22
- 14.√32 to 1 decimal place? (a) 6.0 (b) 5.7 (c) 5.9 (d) 5.8
- 15.√26 to 1 decimal place? (a) 5.4 (b) 5.3 (c) 5.1 (d) 5.2
- 16.Best estimate of 4364 ÷ 46? (a) 87 (b) 8700 (c) 870
- 17.Best estimate of 2463 ÷ 72? (a) 350 (b) 35 (c) 3500
- 18.Best estimate of 2958 ÷ 77? (a) 370 (b) 37 (c) 3700
- 19.√84 to 1 decimal place? (a) 9.2 (b) 9.5 (c) 9.3 (d) 9.4
- 20.√58 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.4 (d) 7.7
- 21.Best estimate of 2697 ÷ 67? (a) 390 (b) 39 (c) 3900
- 22.Best estimate of 1913 ÷ 46? (a) 380 (b) 38 (c) 3800
- 23.√61 to 1 decimal place? (a) 7.9 (b) 7.7 (c) 7.6 (d) 7.8
- 24.√92 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.7 (d) 9.4
- 25.Best estimate of 1904 ÷ 61? (a) 3200 (b) 32 (c) 320
- 26.Best estimate of 3286 ÷ 47? (a) 66 (b) 660 (c) 6600
- 27.Best estimate of 2894 ÷ 52? (a) 5800 (b) 580 (c) 58
- 28.√76 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 9.0 (d) 8.7
- 29.Best estimate of 4496 ÷ 82? (a) 5600 (b) 56 (c) 560
- 30.√46 to 1 decimal place? (a) 6.7 (b) 6.9 (c) 7.0 (d) 6.8
- 31.√65 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.4 (d) 8.1
- 32.Best estimate of 2395 ÷ 52? (a) 480 (b) 48 (c) 4800
- 33.Best estimate of 4200 ÷ 56? (a) 70 (b) 700 (c) 7000
- 34.Best estimate of 1964 ÷ 37? (a) 490 (b) 4900 (c) 49
- 35.√82 to 1 decimal place? (a) 9.3 (b) 9.2 (c) 9.1 (d) 9.4
- 36.Best estimate of 4280 ÷ 63? (a) 710 (b) 7100 (c) 71
- 37.Best estimate of 644 ÷ 23? (a) 3200 (b) 320 (c) 32
- 38.Best estimate of 2612 ÷ 82? (a) 330 (b) 33 (c) 3300
- 39.Best estimate of 562 ÷ 36? (a) 1400 (b) 140 (c) 14
- 40.√40 to 1 decimal place? (a) 6.5 (b) 6.3 (c) 6.6 (d) 6.4
Answer key
- 9.8
- 80
- 24
- 64
- 8.4
- 48
- 81
- 7.9
- 105
- 6.2
- 8.6
- 44
- 22
- 5.7
- 5.1
- 87
- 35
- 37
- 9.2
- 7.6
- 39
- 38
- 7.8
- 9.6
- 32
- 66
- 58
- 8.7
- 56
- 6.8
- 8.1
- 48
- 70
- 49
- 9.1
- 71
- 32
- 33
- 14
- 6.3
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