Twenty-four ways to clock up a new score
Linton Waters tests the latest edition of a card game that exploits a special number
The number 24 has intrigued us for centuries. Much of its allure is attributable to the fact that it is a comfortably small number with lots of factors. This means, among other things, that there are many different ways of making 24 by combining two or more whole numbers using ordinary rules of arithmetic. For example (1+2+3)x4=24.
In South Africa last summer I met representatives of a financial services company who run inter-school tournaments called Maths 24. Pupils work in teams; four dice are rolled and the numbers called out. The first team to make 24 using the four numbers scores a point. Cheap, easy and motivating, the game undoubtedly helps improve mental calculating fluency.
Perhaps we should be seeking sponsorship for similar events in the UK. In the meantime, Bob Sun, a Chinese American, has taken the same idea and built a company around it. His 24 Game comes in different editions but the challenge is essentially the same. Pupils select or are dealt cards with four digits on them and see how quickly they can combine them to make 24. To get the idea, see how long it takes you to make 24 using 7, 9, 2 and 4. This is a level 3 challenge. Bob Sun has extended the idea to cover fractions, decimals, double digits and so on.
The cards are bright and sturdy, the rules easy to learn and, as reported by Victoria Neumark in the Maths Extra May 24, 1996. The game quickly proves popular with a wide range of children in school.
A recent addition is the Jumping Levels Math Program (grit your teeth and ignore the Americanisms which, in places, make the publicity material unintelligible). Individual pupils in a class are tested against the clock and are awarded a sticker when they succeed at their next level. Progress is displayed on a class poster. Level 1 demands solving three easy cards, randomly chosen, in 30 seconds using only addition andor subtraction. Level 7 demands six difficult cards solved using multiplication andor division in three minutes. There is a similar Family Link Kit in which all the family can record their progress. It was probably unfair to test it on my family trip to France. Tolerated while it rained, it didn't match the appeal of cycling and swimming when the sun was out.
We need to encourage more effective mental calculating competencies among our pupils. Games such as the 24 Game can play a positive part by providing practice and motivation. I am less convinced that it is necessary to invest in such elaborate schemes to reap the benefits of an essentially simple idea.
Linton Waters is Shropshire County Adviser for Mathematics