Rounding Off and Estimation Worksheet
How to do it in your head (Round, then work): Round each number: 2-digit numbers to the nearest ten, 3-digit numbers to the nearest hundred. Do the easy sum with the round numbers. Choose the option closest to your estimate.
NameDateTime takenScore ___ / 40
- 1.Best estimate of 68 × 93? (a) 630 (b) 63000 (c) 6300
- 2.Best estimate of 135 + 851? (a) 1000 (b) 1200 (c) 800
- 3.Best estimate of 626 + 244? (a) 800 (b) 1000 (c) 600
- 4.Best estimate of 72 × 54? (a) 3500 (b) 350 (c) 35000
- 5.Best estimate of 871 + 154? (a) 1100 (b) 900 (c) 1300
- 6.Best estimate of 96 × 28? (a) 3000 (b) 30000 (c) 300
- 7.Best estimate of 644 + 699? (a) 1100 (b) 1300 (c) 1500
- 8.Best estimate of 565 + 382? (a) 1200 (b) 1000 (c) 800
- 9.Best estimate of 59 × 93? (a) 540 (b) 5400 (c) 54000
- 10.Best estimate of 785 + 138? (a) 700 (b) 1100 (c) 900
- 11.Best estimate of 132 + 642? (a) 500 (b) 700 (c) 900
- 12.Best estimate of 98 × 21? (a) 20000 (b) 2000 (c) 200
- 13.Best estimate of 441 + 746? (a) 1100 (b) 1300 (c) 900
- 14.Best estimate of 672 + 319? (a) 1200 (b) 800 (c) 1000
- 15.Best estimate of 96 × 57? (a) 600 (b) 6000 (c) 60000
- 16.Best estimate of 170 + 193? (a) 600 (b) 400 (c) 200
- 17.Best estimate of 712 + 559? (a) 1500 (b) 1300 (c) 1100
- 18.Best estimate of 16 × 46? (a) 10000 (b) 100 (c) 1000
- 19.Best estimate of 123 + 490? (a) 800 (b) 400 (c) 600
- 20.Best estimate of 16 × 56? (a) 120 (b) 1200 (c) 12000
- 21.Best estimate of 230 + 608? (a) 1000 (b) 800 (c) 600
- 22.Best estimate of 87 × 36? (a) 3600 (b) 360 (c) 36000
- 23.Best estimate of 38 × 71? (a) 28000 (b) 280 (c) 2800
- 24.Best estimate of 66 × 36? (a) 2800 (b) 28000 (c) 280
- 25.Best estimate of 287 + 608? (a) 700 (b) 1100 (c) 900
- 26.Best estimate of 34 × 76? (a) 24000 (b) 2400 (c) 240
- 27.Best estimate of 360 + 793? (a) 1200 (b) 1000 (c) 1400
- 28.Best estimate of 14 × 27? (a) 3000 (b) 30 (c) 300
- 29.Best estimate of 165 + 770? (a) 1200 (b) 800 (c) 1000
- 30.Best estimate of 424 + 484? (a) 900 (b) 1100 (c) 700
- 31.Best estimate of 68 × 49? (a) 35000 (b) 350 (c) 3500
- 32.Best estimate of 540 + 230? (a) 900 (b) 700 (c) 500
- 33.Best estimate of 36 × 98? (a) 4000 (b) 400 (c) 40000
- 34.Best estimate of 88 × 71? (a) 6300 (b) 63000 (c) 630
- 35.Best estimate of 50 × 69? (a) 3500 (b) 350 (c) 35000
- 36.Best estimate of 589 + 251? (a) 1100 (b) 900 (c) 700
- 37.Best estimate of 83 × 58? (a) 4800 (b) 480 (c) 48000
- 38.Best estimate of 30 × 49? (a) 15000 (b) 150 (c) 1500
- 39.Best estimate of 131 + 851? (a) 800 (b) 1200 (c) 1000
- 40.Best estimate of 59 × 16? (a) 120 (b) 1200 (c) 12000
Answer key
- 6300
- 1000
- 800
- 3500
- 1100
- 3000
- 1300
- 1000
- 5400
- 900
- 700
- 2000
- 1100
- 1000
- 6000
- 400
- 1300
- 1000
- 600
- 1200
- 800
- 3600
- 2800
- 2800
- 900
- 2400
- 1200
- 300
- 1000
- 900
- 3500
- 700
- 4000
- 6300
- 3500
- 900
- 4800
- 1500
- 1000
- 1200
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