Whenever I think about subtraction, I think of action. Things being reduced takes action on someones part. Just think of these situations.
- Butterflies on a bush, then some fly away.
- So many fish and then a predator comes and eats some or all of them.
- Five lights are and then three are turned off.
- Twelve grapes in a bunch and then seven are eaten.
- Six bottles of paint are used for a mural and there are only two bottles left after all the painting is done.
- Ten bowling pins are up and after the throw three remain.
If you feel a child is ready you can also introduce the concept of negative numbers (this can be as early as about four years old)...
- It is negative ten degrees outside and then the temperature rises six degrees.
- There are four barefoot children but only seven socks.
- Three hungry split up to look for food and two of them found something to eat.
- Tom drew 25 circles on his paper and grabbed a bunch of Cheerios, but after putting one in each circle there were still 7 empty circles.
My activity suggestion is to have a
Subtraction Scavenger Hunt.
- Prepare enough 3x5 cards or something similar for each student to get three. Write a different subtraction problem (For example 7-5=) on each card.
- Have the children randomly pick their first card (it might be good to work in groups).
- Give them two minutes to find objects or discover a way to represent their problem. (For my example they might pick up seven toy cars and show you five driving away OR seven pencils in a cup and five are taken out.)
- Have the children write down their word problem and show the class if there is time.
- Repeat two more times.
On Saturday I'll be having a guest blogger here. Be sure to come back and check it out : ) And remember to link up any of your math blog posts : )
