If it takes four men one day to build a wall, how long does it take
60,000 men to build a similar wall?
Use your knowledge of angles to work out how many degrees the hour
and minute hands of a clock travel through in different amounts of
Great Granddad is very proud of his telegram from the Queen
congratulating him on his hundredth birthday and he has friends who
are even older than he is... When was he born?
Here's a chance to work with large numbers...
A paradox is a statement that seems to be both untrue and true at the same time. This article looks at a few examples and challenges you to investigate them for yourself.
Use the clocks to investigate French decimal time in this problem.
Can you see how this time system worked?
How many times in twelve hours do the hands of a clock form a right
angle? Use the interactivity to check your answers.
Which segment on a digital clock is lit most each day? Which
segment is lit least? Does it make any difference if it is set to
12 hours or 24 hours?
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?
Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?
Use the interactivity to move Mr Pearson and his dog. Can you move
him so that the graph shows a curve?
These clocks have only one hand, but can you work out what time
they are showing from the information?
Can you create a story that would describe the movement of the man
shown on these graphs? Use the interactivity to try out our ideas.
My measurements have got all jumbled up! Swap them around and see
if you can find a combination where every measurement is valid.
Alice's mum needs to go to each child's house just once and then
back home again. How many different routes are there? Use the
information to find out how long each road is on the route she
Not everybody agreed that the Third Millennium actually began on January 1st 2000. Find out why by reading this brief article.
This article explains how Greenwich Mean Time was established and in fact, why Greenwich in London was chosen as the standard.
Two engines, at opposite ends of a single track railway line, set
off towards one another just as a fly, sitting on the front of one
of the engines, sets off flying along the railway line...
Can you order pictures of the development of a frog from frogspawn
and of a bean seed growing into a plant?
Can you put these mixed-up times in order? You could arrange them in a circle.
If Tom wants to learn to cook his favourite supper, he needs to make a schedule so that everything is ready at the same time.
The pages of my calendar have got mixed up. Can you sort them out?
In this matching game, you have to decide how long different events take.
What can you say about when these pictures were taken?
Galileo, a famous inventor who lived about 400 years ago, came up
with an idea similar to this for making a time measuring
instrument. Can you turn your pendulum into an accurate minute
A game for two or more players that uses a knowledge of measuring
tools. Spin the spinner and identify which jobs can be done with
the measuring tool shown.
Every day at noon a boat leaves Le Havre for New York while another
boat leaves New York for Le Havre. The ocean crossing takes seven
days. How many boats will each boat cross during their journey?
A bus route has a total duration of 40 minutes. Every 10 minutes,
two buses set out, one from each end. How many buses will one bus
meet on its way from one end to the other end?
I found these clocks in the Arts Centre at the University of
Warwick intriguing - do they really need four clocks and what times
would be ambiguous with only two or three of them?
Noticing the regular movement of the Sun and the stars has led to a desire to measure time. This article for teachers and learners looks at the history of man's need to measure things.
A train leaves on time. After it has gone 8 miles (at 33mph) the driver looks at his watch and sees that the hour hand is exactly over the minute hand. When did the train leave the station?
This article for teachers suggests ways in which dinosaurs can be a
great context for discussing measurement.
What is the date in February 2002 where the 8 digits are
palindromic if the date is written in the British way?
This investigation explores using different shapes as the hands of
the clock. What things occur as the the hands move.
Sometime during every hour the minute hand lies directly above the hour hand. At what time between 4 and 5 o'clock does this happen?
These two challenges will test your time-keeping!
My cousin was 24 years old on Friday April 5th in 1974. On what day
of the week was she born?
At the time of writing the hour and minute hands of my clock are at
right angles. How long will it be before they are at right angles
This month there is a Friday the thirteenth and this year there are three. Can you explain why every year must contain at least one Friday the thirteenth?
On a digital 24 hour clock, at certain times, all the digits are
consecutive. How many times like this are there between midnight
and 7 a.m.?
During the third hour after midnight the hands on a clock point in
the same direction (so one hand is over the top of the other). At
what time, to the nearest second, does this happen?
In this version of the story of the hare and the tortoise, the race
is 10 kilometres long. Can you work out how long the hare sleeps
for using the information given?
Calendars were one of the earliest calculating devices developed by civilizations. Find out about the Mayan calendar in this article.
Anne completes a circuit around a circular track in 40 seconds.
Brenda runs in the opposite direction and meets Anne every 15
seconds. How long does it take Brenda to run around the track?
On a digital clock showing 24 hour time, over a whole day, how many
times does a 5 appear? Is it the same number for a 12 hour clock
over a whole day?
Follow the journey taken by this bird and let us know for how long
and in what direction it must fly to return to its starting point.
Read this article to find out the mathematical method for working out what day of the week each particular date fell on back as far as 1700.
How far have these students walked by the time the teacher's car
reaches them after their bus broke down?
Nirmala and Riki live 9 kilometres away from the nearest market.
They both want to arrive at the market at exactly noon. What time
should each of them start riding their bikes?
Stuart's watch loses two minutes every hour. Adam's watch gains one
minute every hour. Use the information to work out what time (the
real time) they arrived at the airport.