Arithmetic Series

Pronunciation: /æ.rɪθˈmɛ.tɪk ˈsɪər.iz/ Explain

An arithmetic series is the sum of an arithmetic sequence. For example, the arithmetic series for the sequence { 2, 5, 8, 11 } is 2 + 5 + 8 + 11 = 26.

The general formula for an arithmetic series is S = n · (a0 + an-1) / 2 where:

• a0 is the first number in the sequence,
• an-1 is the last number in the sequence, and
• n is the number of terms.
Applying this to the sequence above, we get:
• a0 = 2,
• an-1 = 11, and
• n = 4.
So,
• S = 4 · ( 2 + 11 ) / 2
• S = 4 · 13 / 2
• S = 52 / 2
• S = 26.
1. McAdams, David E.. All Math Words Dictionary, arithmetic series. 2nd Classroom edition 20150108-4799968. pg 20-21. Life is a Story Problem LLC. January 8, 2015. Buy the book
2. arithmetic progression. merriam-webster.com. Encyclopedia Britannica. Merriam-Webster. Last Accessed 6/12/2018. https://www.merriam-webster.com/dictionary/arithmetic%20progression. Buy the book
3. Kelso, Oscar Lynn, M.A.. Arithmetic for High Schools, Academies, and Normal Schools. pg 265. www.archive.org. The Macmillan Company. 1903. Last Accessed 6/12/2018. http://www.archive.org/stream/arithmeticforhi00kelsgoog#page/n281/mode/1up/search/series. Buy the book

McAdams, David E. Arithmetic Series. 4/12/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/a/arithmeticseries.html.

Revision History

4/12/2019: Changed equations and expressions to new format. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)