Unit #5: Adding and subtracting decimals

Front

What is a decimal?

Back

A decimal is a fraction whose denominator is a power of ten, represented with a decimal point. For example, 0.5 is the decimal representation of 1/2.

Front

How do you add decimals?

Back

To add decimals, align the numbers by the decimal point and add as you would whole numbers, placing the decimal point in the sum directly below the other decimal points.

Front

How do you subtract decimals?

Back

To subtract decimals, align the numbers by the decimal point and subtract as you would whole numbers, placing the decimal point in the difference directly below the other decimal points.

Front

What is the value of 1.00 - 0.15?

Back

0.85

Front

What is the value of 0.40 + 0.20?

Back

0.60

Front

What is the value of 1.25 - 0.15?

Back

1.10

Front

What is the value of 2.25 - 0.10?

Back

2.15

Front

What is the value of 3 × 0.05?

Back

0.15

Front

Back

First, convert all fractions to decimals: 1 + 0.1 + 0.75 - 0.1 + 0.05 = 1.80.

Front

What is the total amount after the transactions: 1.00 - 0.15 + 0.40 + 0.20 - 1.00?

Back

0.45