Decimal Clock
A decimal clock is started at midnight. What time would it show at 6 o'clock in the morning?
Age
11 to 14
Challenge level
Problem
In the late 18th century, a decimal clock was proposed, in which there were 100 'minutes' in one 'hour' and 10 'hours' in one day.
Assuming that such a clock started from 0:00 at midnight, what time would it show when an ordinary clock showed 6am?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
Student Solutions
Answer: 2:50
6 hours = $\frac14$ of 24 hours
$\frac14$ of 10 "hours" = 2.5 "hours"
2.5 "hours" = 2 "hours" and 50 "minutes"