Which pairs of cogs let the coloured tooth touch every tooth on the
other cog? Which pairs do not let this happen? Why?
Sorting the Numbers
Stage: 1 and 2 Challenge Level:
What patterns or relationships have you come across?
Why are these relationships occurring?
What happens when you rotate the smaller/larger square?
What happens when you shift the smaller/larger square up or
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities
can be found here.