The Cuisenaire Gattegno Method Of Teaching Mathematics
summarizes the pupil’s activities in this respect with the phrase ‘finding a score of useful products’, and encourages him by means of interesting experiences associated with the doubling and trebling of numbers, using tests of divisibility and building a table of squares up to 1000. These particular experiences are described in Part IV of Book II of Mathematics and will form the main topic for discussion in this chapter.
Doubling And Halving Numbers Up To 1ooo The pupil has already had some experience in doubling and halving numbers up to 100 and it has already been indicated* how he is assisted at particular hurdles, as when asked to ‘start with 2 and go on doubling till you reach 1000’. For example, it will be remembered that when he reached 256, he was shown the informal method of finding 2 × 256 = 2 × 250 + 2 × 6 = 500 + 12 = 512 Similarly, when asked to ‘go backwards till you reach the number you started with’, he was encouraged to treat each number in the series individually and to say how to find, for example, of 512: of 512 =
of 500 +
of 12 = 250 + 6 = 256
* See Chapter 10.
Published on Nov 18, 2009