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 a decimal representation of 5/10.

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 1.25 + 4.25 + 3.00?

Back

The value is 8.50.

Front

If you pay $20 for gas that costs $16.72, how much change do you get back?

Back

You get back $3.28.

Front

What is the difference between 21.00 and 19.47?

Back

The difference is 1.53.

Front

What is the first step in adding decimals?

Back

The first step is to align the decimal points of the numbers being added.

Front

What do you do if the numbers have different lengths when adding decimals?

Back

You can add zeros to the end of the shorter number to make them the same length.

Front

How do you check your work after adding or subtracting decimals?

Back

You can check your work by reversing the operation: if you added, subtract the sum from one of the original numbers to see if you get the other.

Front

What is the importance of the decimal point in calculations?

Back

The decimal point indicates the value of digits in a number, determining their place value and ensuring accurate calculations.