Today I first had my students do Stranger Pieces of Cake. I started off by reading over the into and giving them 5 minutes to think about number 1. When they were asked to put their findings on the ipads and project them (using airplay) I realized that they were in need of help. I did have one girl say that 2 to the 3/5 power would be like Alice's height increasing by 60 percent. I was excited that she used that description but I needed to lead them to a point where we could explain the problem using ideas we had already learned in Alice...so that we could develop the rule for fractional exponents.
So...I then asked them if they could figure out a problem where they either raised a power to a power or multiplied powers with the same base and the answer was 2^(3/5). Luckily, at least one group in each class eventually came up with 2^(1/5) * 2^(1/5) * 2^(1/5). We related this back to the activity where we developed the rule for exponents that are unit fractions which eventually got us to the idea that the 5th root of 2^3. Anyway...I had to do ALOT of leading through this activity but I really believe that the students have a better chance of remembering the rule for fractional exponents after they have had their "hands on" trying to figure it out themselves.
Confusion Reigns is a good activity that makes students just rethink through a few of the rules they have learned. I LOVE the first problem because so many students didn't pay any attention to the fact that they were adding 2 powers with the same base instead of multiplying. I hope this helps them to pay closer attention to the operation signs in the future.
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