Wednesday, May 6, 2009
We worked on subtraction problems this morning. After teaching them that they can be called "minus" or "subtraction" or "take away" problems, we learned how to read them and then how to use fingers or other manipulative materials to do them.
A really good manipulative material are the magnetic marbles shown in this photo. They are colorful little spheres of plastic with magnets inside just strong enough to make them want to stick to each other in a most pleasing way.
When used as materials for "take away" problems they give a real sense of something being taken away. If the student began, say with a little chain of 8 marbles and then takes 3 of them away the remaining 5 seem to call out to the marbles that have been pulled off.
They're also wonderful when teaching addition problems. When a student combines two a little chains of marbles, they join together with some enthusiasm and integrity as a new combined group.
By the way, if you want to generate your own math worksheets get acquainted with Math Fact Cafe. It allows you to customize your own math worksheets. Free.