Rounding and Decimals:

Place Values After the Decimal Point

Just like each digit in a whole number, each digit behind the decimal point also has a name. You can see in the visual that the names go in the same order in the opposite direction from the whole number place value names. It is important to learn these place value names so you will know where to round when someone asks you to round to certain place value or precision. Understanding these names will also help you with fractions.

This image displays the number 6,781,239,465.724069 and above each number is written the number place value. There is an arrow pointing to the decimal point to add emphasis to it and the numbers after the decimal point are also highlighted to draw attention to them. The place value to the right of the decimal point is labeled Tenths with an emphasis on the 'ths' at the end. The next place value to the right is labeled Hundredths. The 'ths' is again highlighted. Continuing to the right is the Thousandths, Ten Thousandths, Hundred Thousandths, and Millionths. The 'ths' on all of them is emphasized.

In some places around the world, a comma (,) is used to show where the decimal point is in a number. In other places, a period (.) is used for the decimal point. In this course, we will use a period to mark all decimal points and we will sometimes use commas to group the numbers to the left of the decimal point for easier reading. If you are used to a comma as your decimal point, be sure to pay close attention to this detail.

Video Source (08:49 mins) | Transcript

Additional Resources


Practice Problems

  1. Consider the number 0.261354
    For each of the following digits, give its place value:
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5
  2. Consider the number 95.487016
    For each of the following digits, give its place value:
    1. 6
    2. 7
    3. 8
    4. 9
    5. 0

Solutions

    1. 1 = thousandths
    2. 2 = tenths
    3. 3 = ten thousandths
    4. 4 = millionths
    5. 5 = hundred thousandths
      6. (Solution Video | Transcript)
    1. 6 = millionths
    2. 7 = thousandths
    3. 8 = hundredths
    4. 9 = tens
    5. 0 = ten thousandths
      6. (Solution Video | Transcript)