## Sunday, October 26, 2008

### How would you mulitply 11 times 29?

Does it matter what way you work 11 times 29 if you get the correct answer?
1. One way would be to multiply 10 times 29 which is 290 and then add another 29 which is 319.
2. Another way would be to multiply 11 times 30 and which is 330 and subtract one 11 to get 319.
3. Another way would be to add 11 plus 11 plus 11 ... and so on until you have done it 29 times.
4. Another way would be to use the column method. See below.
5. How about using a calculator?
Usually students are drawn towards the method that is easiest. Furthermore, students want what is easiest for them. Reviewing different methods is an excellent way to have students buy into a quicker method. So often I make the mistake of showing one way to do a problem. I think that I'm cheating some of my students when I do this because they lose out on the opportunity to add to their toolbox of methods of solutions. I think that by only showing one method, I'm sending a message that the way I cover is best, and whatever way you used to solve this problem is not as good.
So I think that I need to work harder at showing multiple methods to solve a problem. I need require my students to find multiple methods of solving a problem. At the high school level, it is more about how students are thinking to solve problems. I know they can get a solution. More importantly, how did you come up with it. Justify your thinking.
So, yes it does matter how you solved the problem. The way you solved it might just help me understand it a little bit better.