5.5 Add Decimals

Practice It

100

2.46 + 1.13

3.59

200

2.05 + 1.87

3.92

300

2.91 + 1.8

4.71

400

1.34 + 1.15

2.49

500

1.74 + 0.36

2.1 

Apply It

100

The length of a nickel is 2.1 cm.  What is the combined length of two nickels lying side by side? 

4.2 cm

200

Shawn used 2.5 pounds of ground beef to make hamburgers for a cookout.  He also used 1.32 pounds of ground beef to make spaghetti.  How many total pounds of ground beef did Shawn use?

3.82 pounds

300

Marvin bought 0.6 pounds of almonds and 1.73 pounds of cashews at the store.  What is the total weight of the almonds and cashews he bought?

2.33 pounds

400

Melanie added 1.03 and 0.4. Her result was 1.07. What was her error?

She added 3 hundredths with 4 hundredths. This is a mistake. The actual sum is 1.43.

Add It Up

100

$5 + $0.75

$5.75

200

$3 + $2.90 + $1.05 + $0.05

$7

300

0.003 + 0.03 + 0.3 + 3 + 30

33.333

400

9.09 + 0.91 + 4.75 + 5.25

20

Estimate the Sum

100

Round to the nearest whole number.  Then add.

2.64 + 1.13

3 + 1 = 4

200

Round to the nearest whole number.  Then add.

2.05 + 1.87

2 + 2 = 4

300

Round to the nearest whole number.  Then add.

2.91 + 1.8

3 + 2 = 5

400

Round to the nearest whole number.  Then add.

1.34 + 1.15 

1 + 1 = 2

500

Round to the nearest whole number.  Then add.

1.74 + 0.36

2 + 0 = 2