Adding Decimals
Adding Decimals 2
Estimate
100

43.14 + 5.12 = 

What is 48.26?

100

$43.28 + 31.45

What is $74.73

100

Use front-end estimation to estimate the sum.

2.1 + 4.2 + 1.9

About 7

200

$114.73 + 68.1=

What is $182.83?

200

0.724 + 6.458

What is 7.182

200

Use front-end estimation to estimate the sum.

$12.75 + 26.23 + 35.43

About $60

300

3.529 + 1822.55=

What is 1826.079?

300

1.325 + 0.081

What is 1.406

300

Use rounding to estimate the sum.

13.2 + 1.7 + 8.9

About 24

400

88,888.888 + 123.456 =

What is 89,012.344?

400

43.234+12.953=

56.187

400

Use rounding to estimate the sum.

5.41 + 2.80 + 0.14

About 8.3

500

Manaus, Brazil is a city on the edge of the Amazon Rainforest. On average, the city of Manaus receives 6.3 cm of rain in September. In October, the rainfall average increased by 4.81 cm. What is the total average rainfall for both months in Manaus?

The total average rainfall is 17.41 cm.

500

The silver medalist scored 0.567 points higher than the bronze medalist. The gold medalist scored 0.466 points higher than the silver medalist. The bronze medalist scored 14.933 points. How many points did the silver and gold medalists score?

The silver medalist scored 15.500 points and the gold medalist scored 15.966 points.

500

Giant kelp seaweed can grow 1.85 feet each day. About how long could a kelp that is 39.7 feet long be 3 days later?

The kelp would be about 46 feet. (rounding)

The kelp would be about 33 feet. (front-end estimate)

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