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ERIC Number: EJ775291
Record Type: Journal
Publication Date: 2002-Jun
Pages: 3
Abstractor: ERIC
Reference Count: 0
ISSN: ISSN-0025-5785
90 Minutes on a Sunday Afternoon or: The Proof of the Special MT Issue Is in...
Pinel, Adrian
Mathematics Teaching, n179 p8-10 Jun 2002
This article was written as a result of the author reading "MT177," a special issue dedicated to the teaching of "proof" in mathematics. He used the ideas in this special issue for planning his session "mathematical reasoning and proof," which was part of a weekend course for primary trainees. It consisted of three activities: (1) How many different triangles are there?; (2) What different polygons can you make from a two-piece tangram?; and (3) A prime claim. Proof by exhaustion was evident in the tangram case, but there was also a hint of this with the primes, since the whole numbers had been "modularised" by the columns. Disproof by contradiction was conveyed quite memorably through the primes example. There had been a lot of deduction going on, and some of what had been "proved" could be so described. As a bonus the visual proof for three consecutive numbers had within it the seeds of an inductive proof. The original triangles activity is an interesting one, since there are all three elements of "proof" and "disproof" present. The two-way classification table--arrived at by deciding on what was different--led to the deduction that nine possibilities existed. (Contains 1 endnote.)
Association of Teachers of Mathematics. Unit 7 Prime Industrial Park, Shaftesbury Street, Derby, DE23 8YB, UK. Tel: +44-1332-346599; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A