Add, Subtract, and Multiply Decimals

Adding Decimals

100

4.2 + 3.4

7.6

200

5.2 + 6.75

11.95

300

The most important thing to remember when you add and subtract decimals is to...

Line em up up up - Line up your decimals.

400

12 + 4.56

16.56

500

3.45 + 5.67

9.12

Subtracting Decimals

100

3.4 - 1.2

2.2

200

3.75-2.3

1.45

300

8.7 - 3.65

5.05

400

8 - 1.3

6.7

500

7.57 - 2

5.57

Multiplying Decimals

100

3.4 x 1.5 

5.1

200

2.4 x 0.6

1.44

300

0.75 x 8

6

400

5.2 x 1.3

6.76

500

1.25 x 3.4

4.25

SURPRISE!

100

The answer to an addition problem.

Sum

200

The answer to a subtraction problem.

Difference

300

The answer to a multiplication problem

Product

400

Why is your product less than 4.5 in the following problem?   0.2 x 4.5

You are multiplying 4.5 times a number less than 1. 

500

1.57 x 2.45

3.8465

Word Problems

100

It rained 2.8 inches on Tuesday and 0.64 inches on Wednesday.  How many inches did it rain all together?

3.44 inches

200

Paige earned $25.75 for doing his chores this weekend.  Cody earned $18.95.  How much more did Paige earn compared to Cody?

$6.80

300

Breyton had $72.  He bought a video game for $40.95.  How much money does he have left?

$31.05

400

Catalina runs 3.45 miles.  James runs 1.2 times the distance that Catalina does.  How far does James run?

4.14 miles

500

Place the decimal point in the product and EXPLAIN why you put it there.

2.56 x 1.4 =3584

3.584 because you have 3 places behind your decimal in the problem.