There are two types of rounding techniques used when rounding money. The first rounding is to the nearest dollar, which you learned about in the previous lesson. The second rounding is to the nearest cent.

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When we estimate the cost of something we are purchasing, we are really just rounding decimals. Rounding decimals is exactly the same as rounding whole numbers. A quick review of rounding can be thought of in this way:

Estimation Tune Up!

$1.56

We read this as "one dollar and fifty-six cents" because it is money.

If it were not money we would read it as "one and fifty six hundredths" or "one decimal five six."

Courtesy of ADLC

When rounding money, we can round to the nearest hundredth — where the number 6 is now in the example above, to the nearest tenth — where the number 5 is now, or to the nearest whole number — where the number 1 is now.

Let's round this number to the nearest tenth, as that is the place value that we usually round to when talking about money. In order to do that, you need to look at the number to the RIGHT of the tenths. Look at the 6. Is that number 6 equal to or greater than 5? Yes, it is greater than 5. So that means we can round the tenths place UP by 1.

We no longer have a hundredths place, only a tenths place. So, let's put a zero on the hundredths place. Our new number is 1.60 or $1.60.

REMEMBER, when dealing with decimals numbers to the right of the decimal place, we put a "th" on the end of the word. For example tenTHS or hundredTHS. It is not the same as the whole numbers to the left of the decimal that are tens and hundreds.

Try this activity to practice rounding decimals

  Self-check!