Writing and Naming Decimals
Learning Outcomes
- Name a decimal number
- Given the name of a decimal number, write it in decimal notation
Counting number | Name |
---|---|
[latex]1[/latex] | One |
[latex]10=10[/latex] | Ten |
[latex]10\cdot 10=100[/latex] | One hundred |
[latex]10\cdot 10\cdot 10=1000[/latex] | One thousand |
[latex]10\cdot 10\cdot 10\cdot 10=10,000[/latex] | Ten thousand |
Decimal | Fraction | Name |
---|---|---|
[latex]0.1[/latex] | [latex]\frac{1}{10}[/latex] | One tenth |
[latex]0.01[/latex] | [latex]\frac{1}{100}[/latex] | One hundredth |
[latex]0.001[/latex] | [latex]\frac{1}{1,000}[/latex] | One thousandth |
[latex]0.0001[/latex] | [latex]\frac{1}{10,000}[/latex] | One ten-thousandth |
- The "th" at the end of the name means the number is a fraction. "One thousand" is a number larger than one, but "one thousandth" is a number smaller than one.
- The tenths place is the first place to the right of the decimal, but the tens place is two places to the left of the decimal.
Let’s try naming a decimal, such as [latex]15.68[/latex]. | |
We start by naming the number to the left of the decimal. | fifteen______ |
We use the word "and" to indicate the decimal point. | fifteen and_____ |
Then we name the number to the right of the decimal point as if it were a whole number. | fifteen and sixty-eight_____ |
Last, name the decimal place of the last digit. | fifteen and sixty-eight hundredths |
Name a decimal number.
- Name the number to the left of the decimal point.
- Write "and" for the decimal point.
- Name the "number" part to the right of the decimal point as if it were a whole number.
- Name the decimal place of the last digit.
Exercises
Name each decimal: 1. [latex]4.3[/latex] 2. [latex]2.45[/latex] 3. [latex]0.009[/latex] 4. [latex]-15.571[/latex]. Solution1. | |
[latex]4.3[/latex] | |
Name the number to the left of the decimal point. | four_____ |
Write "and" for the decimal point. | four and_____ |
Name the number to the right of the decimal point as if it were a whole number. | four and three_____ |
Name the decimal place of the last digit. | four and three tenths |
2. | |
[latex]2.45[/latex] | |
Name the number to the left of the decimal point. | two_____ |
Write "and" for the decimal point. | two and_____ |
Name the number to the right of the decimal point as if it were a whole number. | two and forty-five_____ |
Name the decimal place of the last digit. | two and forty-five hundredths |
3. | |
[latex]0.009[/latex] | |
Name the number to the left of the decimal point. | Zero is the number to the left of the decimal; it is not included in the name. |
Name the number to the right of the decimal point as if it were a whole number. | nine_____ |
Name the decimal place of the last digit. | nine thousandths |
4. | |
[latex]-15.571[/latex] | |
Name the number to the left of the decimal point. | negative fifteen |
Write "and" for the decimal point. | negative fifteen and_____ |
Name the number to the right of the decimal point as if it were a whole number. | negative fifteen and five hundred seventy-one_____ |
Name the decimal place of the last digit. | negative fifteen and five hundred seventy-one thousandths |
TRY It
[ohm_question]146224[/ohm_question] [ohm_question]146225[/ohm_question] [ohm_question]146568[/ohm_question] [ohm_question]146569[/ohm_question]example
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. | [latex]6[/latex]._____ |
The decimal part is seventeen hundredths. Mark two places to the right of the decimal point for hundredths. | [latex]6[/latex]._ _ |
Write the numerals for seventeen in the places marked. | [latex]6.17[/latex] |
Answer: 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. | [latex]14[/latex]. _________ |
Mark two places to the right of the decimal point for "hundredths". | [latex]14[/latex].__ __ |
Translate the words after "and" and write the number to the right of the decimal point. | [latex]14.37[/latex] |
Fourteen and thirty-seven hundredths is written [latex]14.37[/latex]. |
try it
[ohm_question]146570[/ohm_question]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.
example
Write twenty-four thousandths as a decimal.Answer: Solution
twenty-four thousandths | |
Look for the word "and". | There is no "and" so start with 0 [latex]0[/latex]. |
To the right of the decimal point, put three decimal places for thousandths. | |
Write the number [latex]24[/latex] with the [latex]4[/latex] in the thousandths place. | |
Put zeros as placeholders in the remaining decimal places. | [latex]0.024[/latex] |
So, twenty-four thousandths is written [latex]0.024[/latex] |
try it
[ohm_question]146571[/ohm_question] [ohm_question]146572[/ohm_question]Licenses & Attributions
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- Question ID 146571, 146572, 146568,146569, 146224, 146225. Authored by: Lumen Learning. License: CC BY: Attribution.
CC licensed content, Shared previously
- Read and Write Decimals. Authored by: James Sousa (Mathispower4u.com). License: CC BY: Attribution.
- Examples: Write a Number in Decimal Notation from Words. Authored by: James Sousa (Mathispower4u.com). License: CC BY: Attribution.
CC licensed content, Specific attribution
- Prealgebra. Provided by: OpenStax License: CC BY: Attribution. License terms: Download for free at http://cnx.org/contents/[email protected].