Adding and Subtracting Decimals Pre-test

Front

What is the process for adding decimals?

Back

To add decimals, align the numbers by the decimal point, add zeros if necessary to make the numbers the same length, and then 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, add zeros if necessary to make the numbers the same length, and then subtract as you would whole numbers, placing the decimal point in the difference directly below the other decimal points.

Front

What is the sum of 13.16 and 5.90?

Back

The sum of 13.16 and 5.90 is 19.06.

Front

If a family drove for 10.9 hours, 8.6 hours, and 12.4 hours, how do you find the total driving time?

Back

To find the total driving time, add the three times together: 10.9 + 8.6 + 12.4 = 31.9 hours.

Front

What is the difference between 5.72 and 3.55?

Back

The difference between 5.72 and 3.55 is 2.17.

Front

How do you determine how far a prediction was off from the actual amount?

Back

To determine how far a prediction was off, subtract the actual amount from the predicted amount. If the prediction was higher, the result will be positive; if lower, it will be negative.

Front

What is the predicted amount of rain for Chicago?

Back

The predicted amount of rain for Chicago was 1.254 inches.

Front

What was the actual amount of rain received in Chicago?

Back

The actual amount of rain received in Chicago was 0.875 inches.

Front

How do you calculate the difference in rainfall prediction?

Back

To calculate the difference in rainfall prediction, subtract the actual amount from the predicted amount: 1.254 - 0.875 = 0.379 inches.

Front

What is the importance of aligning decimal points when performing addition or subtraction?

Back

Aligning decimal points ensures that each digit is in the correct place value, which is crucial for accurate calculations.