Topic 2 Math

ESTIMATION

100

Estimate by 65.62 + 54.32 + 48.09 by rounding each number to the nearest whole number.

66 + 54 + 48 = 168

200

Estimate to find the sum.

358 + 293

700

300

Estimate to find the difference.

15.01 - 4.4 = ?

11

400

Estimate to the nearest whole number to find the sum.

80.01 + 2.89 = ?

83

500

An amusement park has 2 roller coasters.  One is 727 feet long, and the other is is 385 feet long.  If you ride both roller coasters, about how many feet will you travel in all?

1,100 feet

ADDING DECIMALS

100

3.2 + 7.5 = ?

10.7

200

1.82 + 6 = ?

8.82

300

6.52 + 4.18 = ?

10.70 or 10.7

400

25.6 + 13.2 + 6.4 = ?

45.2

500

34.5 + 4 + 6.35 = ?

44.85

SUBTRACTING DECIMALS

100

16.75 - 4.21 = ?

12.54

200

16 - 4.28 = ?

11.72

300

8.4 - 3.8 = ? 

4.6

400

8.5 - 1.7 = ?

6.8

500

78.24 - 5.89 = ?

72.35

SUBTRACT ACROSS ZEROS

100

50 - 42.29 =

7.71

200

60.04 - 32.28 = ?

27.76

300

80.00 - 45.37 = ?

34.63

400

50.03 - 17.98 = ?

32.05

500

60.00 - 25.38 = ?

34.62