Sunday, October 30, 2011

Fun Algebra with Kids

Well... Halloween is usually the time that I introduce algebra a little bit. I tell the students that one number in our number sentence is wearing his Halloween costume (usually I draw a little ghostie). What we have to figure out is, what is the ghostie number?

For example: 3 + 7 = ghost + 2

This requires a clarification of what "=" actually means (an important prerequisite for algebra later on). A child who thinks = means "put the answer here" will say that the ghostie number is 10. 3 + 7 = 10. They will ignore the + 2 since they have no idea how to process it. One of the teachers in my evening class was saying that they have stopped using the word "equal" at her school and instead they say "is the same as." 3 + 7 IS THE SAME AS 8 + 2.

This will be a fun activity for the end of the day on Monday. And then for the rest of the week I can write ghostie problems on the board to start our day. But I want it to be a really concrete concept -- the idea that the variable is a hidden number which you want to figure out, in order to make the statement be true.

P.S. I just tried this concept out on Leah and she loved making it. It's nice that they have to think of a complete equation in advance and then decide what the variable will be -- so they are solving their own problems first before I ask them to solve one of mine. She carefully drew a little witch on her slip of paper to be the costume, but the nice thing about using rubber stamps as variables is that the children who want to keep doing more of this during the year can just get out the box of rubber stamps and make problems for a friend to solve. They can do this ad infinitum.

3 - flower = 0 + 2

flower = ?

1 comment:

Rhoda said...

A nice place to go from here might be Incredible Equations. Look for the original NCTM article in Teaching Children Mathematics, or some of the follow up materials that have sprung up online: http://www.teachervision.fen.com/tv/printables/tv00019s2.pdf