This has been a really good puzzle that learners have enjoyed and it got them thinking and engaged right at the start of a maths lesson.
A new block of flats has been built with 100 flats.
Dave has to paint the numbers from 1 to 100 on the doors.
How many times will he have to paint the number 9?
A lot of learners say 11 as they do not count 90, 91, 92 and so on as they have counted up from 9, 19, 29 and their brain gets into a pattern. Then when they do realise they get to 19 and forget the number 99 has two 9’s in it. The answer is 20. This creates dicussion regarding writing information down, so that learners can visualise what they are doing.