ABSTRACT
This is a relatively easy question, and most people can recall its answer, having memorised it as a result of past experience. However, if the answer is not known, there are many strategies that could be applied to find it, and some are more effective than others. One strategy, often used by children, is to count out two raised fingers on one hand, and then five raised fingers on the other, and then count the total number of raised fingers (the sum strategy). However, a more effective method is to count up from the larger addend. For example, starting at 5 and counting two upwards: ‘5, 6, 7’. Not only does this min strategy require fewer operations (hence saving time and improving accuracy), but it can also be used for impasse problems – such as what is 11 + 2? – which defeat the sum strategy. Of course, to recall a correct solution is the most effective strategy of all, but this requires appropriate past experience. In order to acquire sufficient experience at solving a wide range of problems, the min strategy is therefore an important component of children’s strategy repertoires. However, there are quite substantial individual differences in how quickly this is developed. It appears that the children who are the most adept at the less effective strategies, such as the sum strategy, are those who are more likely to discover the min strategy (e.g., Siegler, 1996).
