Chapter 7 The Study Of Numbers Up To 20
12; 5, 10, 20; 7, 14; 9, 18; 5, 15. 11, 13, 17 and 19 would of course have to be introduced by some other method. Furthermore, it should be a simple matter for pupils to apply their knowledge of ordinal number and see that the length orange plus white can represent eleven, orange plus red, twelve, and so on. Place value need not be stressed as pupils can easily see that the numbers are broken down into one 10 and a number of units.
Study Of A Particular Number Exploration of the number By means of a mat for the particular number, for example 12, pupils read, write and discuss the wide variety of relationships contained in the various lines. With a different mat made by each pupil the teacher can gauge the depth of understanding achieved for each to the ideas presented. Any one line may be expressed in at least half a dozen different ways and there are usually additions, subtractions, multiplications and divisions in abundant variety. The reading and/or writing of these relationships is an important step towards developing the ability to play with figures, to think mathematically and, ultimately, to work mentally. In a given line of a mat for 12, the following are but a few of the expressions which can be given:
Published on Nov 18, 2009