On Jan 22, 2013, at 12:08 PM, Richard Strausz <Richard.Strausz@farmington.k12.mi.us> wrote:

Some of the 18 had many correct and decided on a good strategy, but made a subtraction error early on and therefore didn't get 100%. And, they didn't check their work...

I can believe that, depending on what "some" means.

Can you just ask the teacher if he/she gave hints in the beginning, and if not, how many students had the strategy figured out in the end?

Bob Hansen