Each morning from 8:30-9, students work in small group math centers. One of our most recent centers was called Distributive Doctor. In this center, students practiced multiplying large numbers by splitting them into smaller more manageable groups. An example of this would be 7x12. Multiples of 12 are hard for third graders, but we have known how to make groups of 10 and 2 for a long time. By distributing or decomposing the factor we are able to solve the problem much more easily. We know that 7x10=70 and 7x2=14 so we add 70+14 to find the answer 84. Now we know that 7x12=84. Strategies like decomposing are helpful when students don't have all of their multiplication facts memorized. They give us a way to solve the problem when we don't have the fact memory to help us.
Don't know what decomposing means? Ask your third grader! It's one of our new favorite vocabulary words that we can use not only when talking about multiplying but the coral reef food chain as well.
No comments:
Post a Comment