Proof without Words: Sums of Special Products

by Sidney H. Kung (Jacksonville University)

This article originally appeared in:
Mathematics Magazine
February, 1989

Subject classification(s): Numbers and Computation | Patterns and Sequences
Applicable Course(s): 3.7 Discrete Math | 4.1 Introduction to Proofs

The author presents a visual proof of the formula for the sum of the first n consecutive products: $1 \times 2 + 2 \times 3 + 3 \times 4 +\ldots + n \times (n+1)$.

A pdf copy of the article can be viewed by clicking below. Since the copy is a faithful reproduction of the actual journal pages, the article may not begin at the top of the first page.

To open this file please click here.

These pdf files are furnished by JSTOR.

Classroom Capsules would not be possible without the contribution of JSTOR.

JSTOR provides online access to pdf copies of 512 journals, including all three print journals of the Mathematical Association of America: The American Mathematical Monthly, College Mathematics Journal, and Mathematics Magazine. We are grateful for JSTOR's cooperation in providing the pdf pages that we are using for Classroom Capsules.