Week 5 - Counting Cogs

Instructions

If you coloured one tooth on each cog, which pairs of cogs let the coloured tooth go into every ‘gap’ on the other cog?

Which pairs of cogs do not let the cogs tooth go into every gap of another cog? Why?

Which cogs have you found that work so far?

Which pairs didn’t work? Can you explain why?

How could you predict whether a pair will work before you try them?

What questions would you like to ask?

*Cut out cogs from the print out (at end of this blog) or make your own cogs. I like to make the cogs from cardboard. I made it easier by sticking a pin into the center of the cog and onto a pillow or Styrofoam. I could spin the cogs easier this way.

Materials

You could cut out the cogs from these sheets. https://bhi61nm2cr3mkdgk1dtaov18-wpengine.netdna-ssl.com/wp-content/uploads/2017/03/Counting-cogs-printable.pdf