Writing Decimals
Writing Decimals
Now we will translate the name of a decimal number into decimal notation. We will reverse the procedure we just used.
Let’s start by writing the number six and seventeen hundredths:
| six and seventeen hundredths | |
| The word and tells us to place a decimal point. | ___.___ |
| The word before and is the whole number; write it to the left of the decimal point. | 6._____ |
| The decimal part is seventeen hundredths.
|
6._ _ |
| Write the numerals for seventeen in the places marked. | 6.17 |
Example
Write fourteen and thirty-seven hundredths as a decimal.
Solution
| fourteen and thirty-seven hundredths | |
| Place a decimal point under the word ‘and’. | ______. _________ |
| Translate the words before ‘and’ into the whole number and place it to the left of the decimal point. | 14. _________ |
| Mark two places to the right of the decimal point for “hundredths”. | 14.__ __ |
| Translate the words after “and” and write the number to the right of the decimal point. | 14.37 |
| Fourteen and thirty-seven hundredths is written 14.37. |
How to Write a decimal number from its name.
- Look for the word “and”—it locates the decimal point.
- Mark the number of decimal places needed to the right of the decimal point by noting the place value indicated by the last word.
- Place a decimal point under the word “and.” Translate the words before “and” into the whole number and place it to the left of the decimal point.
- If there is no “and,” write a “0” with a decimal point to its right.
- Translate the words after “and” into the number to the right of the decimal point. Write the number in the spaces—putting the final digit in the last place.
- Fill in zeros for place holders as needed.
The second bullet in Step 1 is needed for decimals that have no whole number part, like ‘nine thousandths’. We recognize them by the words that indicate the place value after the decimal – such as ‘tenths’ or ‘hundredths.’ Since there is no whole number, there is no ‘and.’ We start by placing a zero to the left of the decimal and continue by filling in the numbers to the right, as we did above.
Example
Write twenty-four thousandths as a decimal.
Solution
| twenty-four thousandths | |
| Look for the word "and". | There is no "and" so start with 0
|
| To the right of the decimal point, put three decimal places for thousandths. | |
| Write the number 24 with the 4 in the thousandths place. | |
| Put zeros as placeholders in the remaining decimal places. | 0.024 |
| So, twenty-four thousandths is written 0.024 |
Before we move on to our next objective, think about money again. We know that \(\text{\$1}\) is the same as \(\text{\$1.00}.\) The way we write \(\text{\$1}\phantom{\rule{0.2em}{0ex}}\left(\text{or}\phantom{\rule{0.2em}{0ex}}\text{\$1.00}\right)\) depends on the context. In the same way, integers can be written as decimals with as many zeros as needed to the right of the decimal.
Optional Video: Write a Number in Decimal Notation from Words
This lesson is part of:
Introducing Decimals