Decimal Time

Stage: 3 Challenge Level: Challenge Level:2 Challenge Level:2

In France in1793 decimal time was introduced, then abandoned only two years later.

Look at these pairs of times. The one on the left is our time and the clock on the right shows the corresponding French decimal time.


our time - 16.43, French decimal time 6.54

our time - 12.00, French decimal time - 5.00

Can you decipher how French decimal time works?
How did you use the clocks to help you?


A poster of this problem is available here.

Published March 2006,April 2006.