Estimation

division estimation

100

42 / 8 =

40/8=5

200

The solution to a division problem.

Quotient

300

123 / 10 = 

120 / 10 = 12

400

59 / 7 = 

56 / 7 = 8

500

44 / 6 = 

42  / 6 = 7

Rounding

100

Round 56 to the nearest 10

60

200

Round 349 to the nearest ten.

350

300

Round 2,264 to the nearest hundred.

2,300

400

Round 3,499 to the nearest thousand.

3,000

500

Wycliffe has 5,555 marbles in his collection. When asked how many he has to the nearest hundred, he should say:__________

5,600

Estimation: Addition

100

Using front-end estimation to the nearest 10: 46 + 72 =

50 + 70 = 120

200

Using front-end estimation to the nearest hundred: 324 + 649 =

300 + 600 = 900

300

Using front-end estimation to the nearest hundred: 11,068 + 3,876 =

11,100 + 3,900 = 15,000

400

Using front-end estimation to the nearest hundred: 423 + 513 + 892 =

400 + 500 + 900 = 1,800

500

Using front-end estimation to the nearest thousand: 724 + 1,425 + 3,512

1,000 + 1,000 + 4,000 = 6,000

Estimation: Subtraction

100

Using front-end estimation to the nearest ten: 65 - 27

70 - 30 = 40

200

Using front-end estimation to the nearest ten: 148 - 59 =

150 - 60 = 90

300

Using front-end estimation to the nearest hundred: 629 - 563

600 - 600 = 0

400

Using front-end estimation to the nearest hundred: 4,477 - 2,546

4,500 - 2,500

500

Using front-end estimation to the nearest thousand: 51,875 - 22,129

52,000 - 22,000 = 30,000

Estimation: Multiplication

100

Using front-end estimation to the nearest 10: 32 x 9

30 x 10 = 300

200

Using front-end estimation to the nearest ten: 45 x 9

50 x 10 = 500

300

Using front-end estimation to the nearest hundred: 325 x 94

300 x 100 = 30,000

400

Using front-end estimation to the nearest hundred: 567 x 329

600 x 300 = 180,000

500

Using front-end estimation to the nearest hundred: 2,455 x 196

2,500 x 200 = 500,000