Why do this
is good for children who are confident with large
numbers but need practice in finding combinations using a
What is the smallest number of lenses a family could
What is the greatest number of lenses a family could
How do you know you haven't got that combination
Children could investigate what would happen if some of the
families have five eyes.
It might be helpful for some children to use counters with either
three or four dots on to represent the eyes.