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What Are the Rounding Steps in Math?

by Lynda Schwartz

In life, an exact number is not always required, and this is where estimation comes into play. Rounding is a form of estimation that changes a number slightly based on its value or the value of the number to its right. The proper steps ensure you round the correct number in the correct direction.

Place Value

You need to know what place you are rounding before solving the equation. The places start with tenths, and then increase by tenfold as the numbers move to the right. Making the second number the hundredths places, the third number thousandths and so on. When you know the place, you can determine whether the number should be raised or stay the same.

Determine Direction

When rounding decimals, the value of the number to the right of the place you are rounding determines the fate of that place. If the value of the neighboring digit is five or greater, you increase the place by one, while a value less than five causes the number to remain unchanged. For example, when rounding 3.142 to the tenths place, look at the hundredths place, which has a value of four. In this example, the tenths place would remain unchanged.

Drop the Remainder

Once you round the place, you drop the numbers sitting to its right. In the previous example, you rounded the number 3.142 to the tenths place. After the rounding, the four and two would drop, leaving the estimated number 3.1. If you rounded the number, 5.875 to the tenth place, the number would change to 5.9, and you would drop the seven and the five.

Whole Numbers

Whole numbers round just like decimals, but the tens, hundreds and thousands move from the right to left. If you are rounding the number 568 to the tenths place, the number will change to 570. Unlike decimals, you do not drop the numbers after the rounded number. Another example, when 5,537,876 is rounded to the ten thousands place; the number would change to 5,540,000. If you dropped the numbers after the ten-thousandths place, the number would change to 5,540, which would not make it a usable estimate of the original number.

About the Author

Lynda Schwartz is a fitness professional who began writing in 2004. She has contributed to "Women's Day" and "Good Housekeeping" magazines, as well as covered fitness and well-being for online publications. Schwartz holds a bachelor's degree in exercise science and health promotion.

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