Decimals

Decimal Sense

100

l---l---l---A---l---l---l---l---l---l---l

0                                              1

A=0.3

200

l---l---l---l---l---l---l---l---l---B---l

0.4                                           0.5

B=0.49

300

l---l---C---l---l---l---l---l---l---l---l

0.7                                          0.8

C=0.72

400

l---l---l---l---l---l---l---l---D---l---l

6.41                                         6.42

D=6.418

500

l---E---l---l---l---l---l---l---l---l---l

9.21                                        9.22

E=9.211

Decimal & Place Value

100

Find the place and value of the underlined digit.

798.072

hundredths, 0.07

200

Find the place and value of the underlined digit.

81.327

tenths, 0.3

300

Write in expanded form. 

13.152

10+3+0.1+0.05+0.002

400

Write in expanded form. 

9,734.093

9,000+700+30+4+0.0+0.09+0.003

500

Write as a fraction in simplest form. 

0.6

6/10=3/5

Add Decimals

100

Add.

0.39+0.5=

0.89

200

Add.

3.45+ 4.2+ 7.34=

14.99

300

Add.

97.602+5.9

103.502

400

Add.

r+8.634

when r=17.05

25.684

500

Add to compare. 

7/10 + 1/10 ________1.15 + 0.4

8/10=.8 ___1.55

<

Subtract Decimals

100

Subtract.

0.978-.6=

0.378

200

Subtract.

8.6-0.314=

8.286

300

Subtract.

40.1-7.39=

32.71

400

Subtract.

19.42-s 

when s=1.193

18.227

500

Subtract to compare. 

6.034-2.95_____ 74/100-16/100

3.084____58/100=.58

<

Estimating Decimals

100

Front end estimate. 

4.983-0.77=

4-0=4.00

200

Front end estimate.

196.4+814.933=

8+1=900.000

300

Round to estimate. 

3.89-1.158=

3.89=4

1.158=1

4-1=3.000

400

Round to estimate.

30.64+19.3=

30.64=31

19.3=19

31+19=50

500

Front end estimate AND round to find where your exact answer will be between. 

78.5-14.371=

7-1=60.000

78.5=79

14.371=14

79-14=65 

so the exact answer is between 60.000 and 65.000