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?
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
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.?
Number problems at primary level that require careful consideration.
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?
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.
My cousin was 24 years old on Friday April 5th in 1974. On what day
of the week was she born?
Countries from across the world competed in a sports tournament. Can you devise an efficient strategy to work out the order in which they finished?
You cannot choose a selection of ice cream flavours that includes totally what someone has already chosen. Have a go and find all the different ways in which seven children can have ice cream.
Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.
How could you put these three beads into bags? How many different ways can you do it? How could you record what you've done?
Can you order pictures of the development of a frog from frogspawn
and of a bean seed growing into a plant?
These rectangles have been torn. How many squares did each one have
inside it before it was ripped?
In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication?
Cut differently-sized square corners from a square piece of paper
to make boxes without lids. Do they all have the same volume?
What is the date in February 2002 where the 8 digits are
palindromic if the date is written in the British way?
Find the values of the nine letters in the sum: FOOT + BALL = GAME
Can you draw a square in which the perimeter is numerically equal
to the area?
Can you help the children find the two triangles which have the
lengths of two sides numerically equal to their areas?
This practical challenge invites you to investigate the different
squares you can make on a square geoboard or pegboard.
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
Can you put the numbers from 1 to 15 on the circles so that no
consecutive numbers lie anywhere along a continuous straight line?
An investigation that gives you the opportunity to make and justify
Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
Can you substitute numbers for the letters in these sums?
Investigate all the different squares you can make on this 5 by 5 grid by making your starting side go from the bottom left hand point. Can you find out the areas of all these squares?
What can you say about these shapes? This problem challenges you to create shapes with different areas and perimeters.
If we had 16 light bars which digital numbers could we make? How
will you know you've found them all?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
Can you replace the letters with numbers? Is there only one solution in each case?
When newspaper pages get separated at home we have to try to sort
them out and get things in the correct order. How many ways can we
arrange these pages so that the numbering may be different?
A thoughtful shepherd used bales of straw to protect the area
around his lambs. Explore how you can arrange the bales.
The letters in the following addition sum represent the digits 1
... 9. If A=3 and D=2, what number is represented by "CAYLEY"?
What could the half time scores have been in these Olympic hockey matches?
Use the numbers and symbols to make this number sentence correct. How many different ways can you find?
Can you work out some different ways to balance this equation?
What is the smallest number of tiles needed to tile this patio? Can
you investigate patios of different sizes?
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
In this matching game, you have to decide how long different events take.
My local DIY shop calculates the price of its windows according to the area of glass and the length of frame used. Can you work out how they arrived at these prices?
What happens when you round these numbers to the nearest whole number?
What happens when you round these three-digit numbers to the nearest 100?
If you have three circular objects, you could arrange them so that
they are separate, touching, overlapping or inside each other. Can
you investigate all the different possibilities?
Have a go at balancing this equation. Can you find different ways of doing it?
Ana and Ross looked in a trunk in the attic. They found old cloaks
and gowns, hats and masks. How many possible costumes could they
Use two dice to generate two numbers with one decimal place. What happens when you round these numbers to the nearest whole number?
How many ways can you find of tiling the square patio, using square
tiles of different sizes?
Follow the clues to find the mystery number.
These practical challenges are all about making a 'tray' and covering it with paper.
The pages of my calendar have got mixed up. Can you sort them out?