Prime factors 2, 3, 5, (11) - multiplication session 4/3

The key idea here is to start noticing when numbers have prime factors of 2, 3, 5, and possibly 11.

Activities
Guess the prime factors game - I could start this as a game of pelmanism and explorers have to turn over cards with no more than one difference in colour coding - I can ask about what they think the colour coding is.  It would be a good activity to ...
Organise them into a grid (just two of the colours maybe)
100 square sieve - explorers can colour a corner of the numbers in a hundred square to show which
prime factors they have.
breaking numbers down into prime factors - division of numbers or just look into calculator method.
Grid game with attributes - think of attributes such as human, lion, etc as being numbers.
Project - create a system that could be used to show prime factors of numbers
example resource linked to Alchemy with air, water, fire and earth being 2, 3, 5, 11
create a tarot like deck of number cards that people have to guess which number each one is given the clues
Create a set of numbers that explorers must take if they want to work on it.
Discuss if we want different systems.
Need for a system with lots of possible base elements (primes)