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Tweedle Dum and Tweedle Dee

Two brothers were left some money, amounting to an exact number of pounds, to divide between them. DEE undertook the division. "But your heap is larger than mine!" cried DUM...

Sum Equals Product

The sum of the numbers 4 and 1 [1/3] is the same as the product of 4 and 1 [1/3]; that is to say 4 + 1 [1/3] = 4 � 1 [1/3]. What other numbers have the sum equal to the product and can this be so for any whole numbers?

Special Sums and Products

Find some examples of pairs of numbers such that their sum is a factor of their product. eg. 4 + 12 = 16 and 4 × 12 = 48 and 16 is a factor of 48.

A Chance to Win?

Age 11 to 14 Challenge Level:

Imagine you start by choosing a black card and then choose two red cards:

Your amount Your bet You chose Result
£128 £64 black -£64
£64 £32 red +£32
£96 £48 red +£48


Keep a record of the outcome from laying down the cards in different orders.
What do you notice?

How is your total amount of money affected by a win?
How is it affected by a loss?