I am thinking of three sets of numbers less than 101. Can you find
all the numbers in each set from these clues?
I am thinking of three sets of numbers less than 101. They are the
red set, the green set and the blue set. Can you find all the
numbers in the sets from these clues?
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
Can you work out some different ways to balance this equation?
Norrie sees two lights flash at the same time, then one of them
flashes every 4th second, and the other flashes every 5th second.
How many times do they flash together during a whole minute?
Have a go at balancing this equation. Can you find different ways of doing it?
Nearly all of us have made table patterns on hundred squares, that
is 10 by 10 grids. This problem looks at the patterns on
differently sized square grids.
Can you find any perfect numbers? Read this article to find out more...
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
Four of these clues are needed to find the chosen number on this
grid and four are true but do nothing to help in finding the
number. Can you sort out the clues and find the number?
This package will help introduce children to, and encourage a deep
exploration of, multiples.
You can make a calculator count for you by any number you choose.
You can count by ones to reach 24. You can count by twos to reach
24. What else can you count by to reach 24?
Can you find the chosen number from the grid using the clues?
Pat counts her sweets in different groups and both times she has
some left over. How many sweets could she have had?
Can you complete this jigsaw of the multiplication square?
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
Help share out the biscuits the children have made.
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
Factor track is not a race but a game of skill. The idea is to go round the track in as few moves as possible, keeping to the rules.
Look at three 'next door neighbours' amongst the counting numbers. Add them together. What do you notice?
This activity focuses on doubling multiples of five.
Investigate which numbers make these lights come on. What is the smallest number you can find that lights up all the lights?
Becky created a number plumber which multiplies by 5 and subtracts
4. What do you notice about the numbers that it produces? Can you
explain your findings?
Number problems at primary level that may require determination.
Number problems at primary level to work on with others.
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
Which pairs of cogs let the coloured tooth touch every tooth on the
other cog? Which pairs do not let this happen? Why?
Can you place the numbers from 1 to 10 in the grid?
If there is a ring of six chairs and thirty children must either
sit on a chair or stand behind one, how many children will be
behind each chair?
Use this grid to shade the numbers in the way described. Which
numbers do you have left? Do you know what they are called?
Can you work out what a ziffle is on the planet Zargon?
56 406 is the product of two consecutive numbers. What are these
There are ten children in Becky's group. Can you find a set of
numbers for each of them? Are there any other sets?
Look at the squares in this problem. What does the next square look
like? I draw a square with 81 little squares inside it. How long
and how wide is my square?
On the planet Vuv there are two sorts of creatures. The Zios have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zios and how many Zepts were there?
Follow the clues to find the mystery number.
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?
These red, yellow and blue spinners were each spun 45 times in
total. Can you work out which numbers are on each spinner?
If you have only four weights, where could you place them in order
to balance this equaliser?
How many different shaped boxes can you design for 36 sweets in one
layer? Can you arrange the sweets so that no sweets of the same
colour are next to each other in any direction?
Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?
This article for teachers describes how number arrays can be a
useful reprentation for many number concepts.
An investigation that gives you the opportunity to make and justify
In this problem we are looking at sets of parallel sticks that
cross each other. What is the least number of crossings you can
make? And the greatest?
Are these domino games fair? Can you explain why or why not?
An environment which simulates working with Cuisenaire rods.
Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?