Bernard Bagnall recommends some primary school problems which use
numbers from the environment around us, from clocks to house
Where can you draw a line on a clock face so that the numbers on
both sides have the same total?
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.
Which times on a digital clock have a line of symmetry? Which look
the same upside-down? You might like to try this investigation and
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?
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?
These two challenges will test your time-keeping!
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?
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
These clocks have only one hand, but can you work out what time
they are showing from the information?
Describe what Emma might be doing from these pictures of clocks
which show important times in her day.
Can you put these mixed-up times in order? You could arrange them in a circle.
Can you put these times on the clocks in order? You might like to arrange them in a circle.
How many times in twelve hours do the hands of a clock form a right
angle? Use the interactivity to check your answers.
These clocks have been reflected in a mirror. What times do they
This investigation explores using different shapes as the hands of
the clock. What things occur as the the hands move.