Copyright © University of Cambridge. All rights reserved.

'Planet Plex Time' printed from http://nrich.maths.org/

Show menu

Planet Plex Time


On Planet Plex, there are only six hours in a day but the days of the week are the same as ours. Arog the alien lives on Planet Plex.

Here is a clock which shows how Arog spends each hour of the day during the week:

between 0 and 1 o'clock - gets up; 1-2 o'clock - school; 2-3 o'clock - lunch time; 3-4 o'clock - play; 4-5 o'clock - dinner and 5-6 o'clock - sleeping.

What time does school start?

Arog starts his dinner at $4$ o'clock. What will he be about to do two hours later? What was he about to do five hours earlier?

Arog gets into bed on Wednesday evening. How long is it until school finishes on Friday?


Why do this problem?

This simple problem focuses on duration and will encourage learners to consider the passing of time in a different context.

Key questions

Can you show me on the clock what time school starts?
Could you use the clock to count how many hours have passed?

Possible extension

Children could have a go at the problem Times of Day.