I am excited for the opportunity tomorrow to present a primary math workshop here in the Comox Valley. This is the perfect time for professional development for teachers as the new school year is about to begin. We will be looking at four important number relationships that we should help young children develop.
One of those relationships is Whole-Part-Part. I know that others refer to this as Part-Part-Whole, but I rearrange those terms quite deliberately. The emphasis is on the WHOLE being pulled into the parts rather than the parts joining together to make the whole. Is is an important difference. For instance, if children take 8 counters they can pull them apart in a number of ways: 4 and 4, 3 and 5, 5 and 3 (which for them is different!), 1 and 7, 6 and 2, etc. Later on when those students begin to add numbers, it will not be surprising to them that those combinations add to 8 — they will have become familiar with them as they decomposed numbers.
No matter what grade your students are in, decomposing numbers is a great way to build up their number sense!