Making 24 - No 2Author(s): John BerrySource: Mathematics in School, Vol. 36, No. 3 (May, 2007), p. 10Published by: The Mathematical AssociationStable URL: http://www.jstor.org/stable/30216023 .

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MAKING 24-No12 by John Berry

This puzzle provides a nice warm-up activity for students from Primary through to the sixth form as a way of getting the brain in gear and as a way of encouraging working in pairs. The rules are quite simple:

~irw

I1 ~ i+ B fdzi+ C

aaaI +:e aaa Bs -- BPEI _ t

000.

I~ ;;;;;~

~ +-= ~_= ~~~:=+-

~~=i~=~ 1

=- I

Use all four numbers only once to make the number 24 using the operations of arithmetic: adding, subtracting, multiplying and/or dividing. Each number must be used once and only once!

Be careful! Do not muddle up 6s and 9s. The base of the digit is towards the centre. F

....b

. ..

Keywords: Puzzles.

Author John Berry, The Centre for Teaching Mathematics, The University of Plymouth, Plymouth, Devon PL4 8AA. e-mail: jberry@plymouth.ac.uk

10 Mathematics in School, May 2007 The MA web site www.m-a.org.uk

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