Factors and multiples

When Charlie asked his grandmother how old she is, he didn't get a straightforward reply! Can you work out how old she is?

Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

Imagine a machine with four coloured lights which respond to different rules. Can you find the smallest possible number which will make all four colours light up?

These spinners will give you the tens and unit digits of a number. Can you choose sets of numbers to collect so that you spin six numbers belonging to your sets in as few spins as possible?

This task depends on learners sharing reasoning, listening to opinions, reflecting and pulling ideas together.

Which pairs of cogs let the coloured tooth touch every tooth on the other cog? Which pairs do not let this happen? Why?

Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?

I am thinking of three sets of numbers less than 101. Can you find all the numbers in each set from these clues?

I am thinking of three sets of numbers less than 101. They are the red set, the green set and the blue set. Can you find all the numbers in the sets from these clues?

Nearly all of us have made table patterns on hundred squares, that is 10 by 10 grids. This problem looks at the patterns on differently sized square grids.