This problem is designed to intrigue a little. To tackle the problem, pupils will need to be comfortable with manipulating fractions and decimals, and it would be a good idea to have calculators to hand.

It is an excellent way to highlight misconceptions associated with our digital clock, for example that 12.50 is not 0.5 hours after 12.00. It could be a good vehicle for investigating why our clock is based on the number 60 and researching calendar systems of ancient cultures.