Adding and Subtracting Decimals

Concepts

100

What is Step One to Adding and Subtracting Decimals?

Align (line up) the Decimals

200

What is the FIRST thing you should do with a subtraction problem involving positives and negatives?

Change the subtraction to adding the opposite.

300

When You Subtract Decimals you?

Add The Opposite

400

What is additive inverse?

Adding the opposite

500

When should you NOT change the operation of a problems? 

When it already an addition problem.

Adding Negative and Positive Decimals

100

4.56 + (-5.89)

-1.33

200

-2.81 + (-1.45)

-4.26

300

3.1475 + 6.39

9.5375

400

-15.6 + 4.978

-10.622

500

-16.1 + 3207.87

3191.77

Subtracting Negative and Positive Decimals

100

-6.25 - 4.32

-10.57

200

89.32 - (-76.50)

165.82

300

-23.564 - 21.397

-44.961

400

-9.68 - (-7.2534)

-2.4266

500

32.298014 - 74.652

-42.353986

MORE Adding Negative and Positive Decimals

100

-23.32 + -24.01 =

-47.33

200

-10.32 + -23.76 =

-34.08

300

-49.32 + 34.54 =

-14.78

400

-13.56 + 516 =

502.44

500

45.52015 - 49.5=

-3.97985

MORE Subtracting Negative and Positive Decimals

100

-12.34 - (-56.43) =

44.09

200

-23.64 - (-34.32) =

10.68

300

-45.98 - 2.43 =

-48.41

400

-253.03 - (-7.651) =

-245.379

500

45.5 - (-2354.78) =

2400.28