Today we worked on this lovely puzzle from Nrich.
Choose a starting number from a 1-100 square and cross it out.
Then choose a factor or multiple of that number.
Keep crossing out factors or multiples of the last number in the chain.
For example, Charlie started with 60, 30, 6, 96, 16, 32, 8, 56, 7, 21, 42,…
What’s the longest chain you can make?
There is an interactive place to play here
When you are using the activity make sure you only have a bracket at the start and the end … this attempt isn’t quite right:
But it can be fixed by swapping the 60,90,45 and 15 around:
Email Mrs Fleming on [email protected] if you can do better than 38 steps …