Using Models to Add and Subtract Decimals
Estimate Sums and Differences
Rounding Decimals
Adding and Subtracting Decimals
100

How many hundredths are represented by this model?


0.28

100

Estimate the sum by rounding to the nearest one. 

28.23 + 11.84 

38 + 12 = 51

100

Round 164.752 to the nearest hundredth. 

164.75

100

0.734 + 6.458 =

7.182

200

Write an equation that matches this model. 


0.24 + 0.15 = 0.39

200

Estimate the sum by rounding to the nearest one. 

75.38 + 22.04

75 + 22 = 97

200

Round 986.57 to the nearest tenth. 

986.6

200

1.325 - 0.081 =

1.244

300

Write the equation that goes with this model. 


0.38 - 0.07 = 0.31

300

Estimate the difference by rounding to the nearest whole number. 

$14.99 - $3.21

$15 - $3 = $12

300

Round 165.32 to the nearest hundred.

200

300

17 - 0.62=

16.38

400

Write an equation that matches this model. 


0.2 + 0.20 + 0.2 = 0.6

400

Estimate the answer by rounding to the nearest whole number.

12.645 + 11.81 + 12.3 

13 + 12 + 12 = 37

400

Round 43,120.555 to the nearest tenth.

43,120.6

400

248 - 31.48 =

216.52

500

Write the equation that goes with this model.

1. 48 - 0.83 = 0.65

500

Estimate the answer by rounding your answer to the tenth. 

0.251 + (0.784 - 0.229) 

0.3 +(0.8 - 0.2) =

0.3 + (0.6) = 0.9

500

Round 1,249.711 to the nearest whole number.

1,250

500

Kash is 52.25 inches tall. His little sister is 24.5 inches tall. How much taller is Kash than his sister? 

27.75 inches 

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