You may also like

problem icon

Clock Hands

This investigation explores using different shapes as the hands of the clock. What things occur as the the hands move.

problem icon

Ten Green Bottles

Do you know the rhyme about ten green bottles hanging on a wall? If the first bottle fell at ten past five and the others fell down at 5 minute intervals, what time would the last bottle fall down?

problem icon

A Child Is Full of ...

My cousin was 24 years old on Friday April 5th in 1974. On what day of the week was she born?


Stage: 2 Challenge Level: Challenge Level:1

Even though this challenge is about times on clocks, the display on a calculator will help you to explore the patterns more easily than trying to write the numbers on paper. So grab a calculator and punch in some "times". A little hand mirror can help check for symmetry and reflections too.

Let us know what you find  by emailing! Please don't worry that your solution is not "complete" - we'd like to hear about anything you have tried. Teachers - you might like to send in a summary of your children's work.

Hurrah! In 2015 we had a solution come in from Jake at St George's C of E primary school
You have to have 1 at the start otherwise it won’t work.
Then when I started to think about it, I realised you could have 0 or 2 to start. You can’t have a number greater than 2 because it is a 24 hour clock.
If you used 8 (which has symmetry) you would have 18:81 and you can’t have 8 in the minutes as the highest number you can have is 59 in the minutes.
I then worked out you could have these times:

0 1:1 0
05:20's good
1 0:0 1
1 1 . 1 1
1 2:5 1
1 5:2 1
2 1:1 5
22:55  Jake

Thanks, that's a good answer, sorry your previous submission got lost in the airways.