A 1s and 2s Challenge
It is hardly surprizing that a question about two numbers can approached at an elementary level. But this challenge goes further and will keep the older students going for quite a while. The aim is simple:
Arrange the digits 1 and 2 in a three by three grid to make six numbers that are all different.
The accompanying notes suggest that two maths problem solving strategies can be used to help solve the problem as well as posing further challenges based on the above.
I have also written a FLASH program that will help in the investigation. It enables you to create lots of arrangements of the 1s and 2s and gives feedabck as to how close you are to making an arrangement in which all the 3-digit numbers that you make are different.