Decimal Number

Pronunciation: /ˈdɛs.ə.məl ˈnʌm.bər/ Explain

Decimal Numbers Not Decimal Numbers 3.52 4.00 0.005 74 7/7 12/15 3 7/8 10102 Table 1: Examples

A decimal number is a real number expressed in base 10 that may or may not have a decimal point.[2]

Figure 1: Parts of a decimal number.

A decimal number has a whole part and a decimal part. In the number 32.67, 32 is the whole part and 67 is the decimal part. The whole part is always to the left of the decimal point. The decimal part is always to the right of the decimal point.

Understanding Check

Use the mouse to click on each answer until the correct answer appears. When you have selected the answers for each row, click on 'Check Answer'.

Decimal Number
3.754	754 is the Click to Selectwhole partdecimal part Correct. '754' is to the right of the decimal point, so it is the decimal part.Incorrect. '754' is to the right of the decimal point. It is the decimal part.Click on 'Click to Select' to select the correct answer, then click 'Check Answer'.	3 is the Click to Selectwhole partdecimal part Correct. '3' is to the left of the decimal point, so it is the whole part.Incorrect. '3' is to the left of the decimal point. It is the whole part.Click on 'Click to Select' to select the correct answer, then click 'Check Answer'.	Check Answer

Place Values

For decimals, the place values are in multiples of ten. Take the number style="color:red;">427.

• The digit 7 is in the one's place.
• The digit 2 is in the ten's place. (1×10 = 10)
• The digit 4 is in the hundred's place. (10×10 = 100)

Now take the number 427.56.

• The digit 5 is in the tenths place. (1 ÷ 10 = 1/10)
• The digit 6 is in the hundredths place. (1/10 ÷ 10 = 1/100)

Understanding Check

Use the mouse to click on each answer until the correct answer appears. When you have selected the answers for each row, click on 'Check Answer'.

Decimal Number	Digit	is in the ?'th place
42.15	2	is in the Click to Selecttensonestenthshundredths place.	Check AnswerClick on 'Click to Select' until the correct answer appears, then click on Check Answer.Yes, the digit 2 is in the one's place.No, the digit 2 is in the one's place.
37.92	3	is in the Click to Selecttensonestenthshundredths place.	Check AnswerClick on 'Click to Select' until the correct answer appears, then click on Check Answer.Yes, the digit 3 is in the ten's place.No, the digit 3 is in the ten's place.
65.14	4	is in the Click to Selecttensonestenthshundredths place.	Check AnswerClick on 'Click to Select' until the correct answer appears, then click on Check Answer.Yes, the digit 4 is in the hundredths place.No, the digit 4 is in the hundredths place.
32.97	9	is in the Click to Selecttensonestenthshundredths place.	Check AnswerClick on 'Click to Select' until the correct answer appears, then click on Check Answer.Yes, the digit 9 is in the tenths place.No, the digit 9 is in the tenths place.

References

1. McAdams, David E.. All Math Words Dictionary, decimal number. 2nd Classroom edition 20150108-4799968. pg 54. Life is a Story Problem LLC. January 8, 2015. Buy the book
2. decimal. merriam-webster.com. Encyclopedia Britannica. Merriam-Webster. Last Accessed 7/3/2018. http://www.merriam-webster.com/dictionary/decimal. Buy the book
3. Jones, Burton. Elementary Concepts of Mathematics. pp 99-104. www.archive.org. MacMillan and Company. 1947. Last Accessed 7/3/2018. http://www.archive.org/stream/elementaryconcep029487mbp#page/n120/mode/1up/search/decimal. Buy the book
4. Halstead, George Bruce. On the foundation and technic of arithmetic. www.archive.org. The Open Court Publishing Company. 1912. Last Accessed 7/3/2018. http://www.archive.org/stream/50400297#page/n4/mode/1up. Buy the book

More Information

• McAdams, David E.. Notation. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 3/12/2009. https://www.allmathwords.org/en/n/notation.html.

Cite this article as:

McAdams, David E. Decimal Number. 4/18/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/d/decimalnumber.html.

Image Credits

• All images and manipulatives are by David McAdams unless otherwise stated. All images by David McAdams are Copyright © Life is a Story Problem LLC and are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Revision History

4/18/2019: Updated equations and expressions to the new format (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
7/3/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
1/22/2010: Added "References". (McAdams, David E.)
7/10/2008: Added vocabulary links and figure 1. (McAdams, David E.)
4/14/2008: Reworded definition, added More Information. (McAdams, David E.)
2/14/2008: Corrected spelling errors. (McAdams, David E.)
10/14/2007: Added decimal place. (McAdams, David E.)
7/12/2007: Initial version. (McAdams, David E.)