How can you use just one weighing to find out which box contains
the lighter ten coins out of the ten boxes?
There are ten children in Becky's group. Can you find a set of
numbers for each of them? Are there any other sets?
Ben’s class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
How many different sets of numbers with at least four members can
you find in the numbers in this box?
The planet of Vuvv has seven moons. Can you work out how long it is
between each super-eclipse?
56 406 is the product of two consecutive numbers. What are these
There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?
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?
What is the remainder when 2^2002 is divided by 7? What happens
with different powers of 2?
Investigate the smallest number of moves it takes to turn these
mats upside-down if you can only turn exactly three at a time.
What happens if you join every second point on this circle? How
about every third point? Try with different steps and see if you
can predict what will happen.
In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?
The discs for this game are kept in a flat square box with a square
hole for each disc. Use the information to find out how many discs
of each colour there are in the box.
An investigation that gives you the opportunity to make and justify
Can you work out the arrangement of the digits in the square so
that the given products are correct? The numbers 1 - 9 may be used
once and once only.
Can you find any perfect numbers? Read this article to find out more...
Investigate the different shaped bracelets you could make from 18 different spherical beads. How do they compare if you use 24 beads?
48 is called an abundant number because it is less than the sum of
its factors (without itself). Can you find some more abundant
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
Number problems at primary level that may require determination.
Number problems at primary level to work on with others.
Can you make square numbers by adding two prime numbers together?
Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?
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?
An environment which simulates working with Cuisenaire rods.
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
Nine squares with side lengths 1, 4, 7, 8, 9, 10, 14, 15, and 18 cm can be fitted together to form a rectangle. What are the dimensions of the rectangle?
Arrange the four number cards on the grid, according to the rules,
to make a diagonal, vertical or horizontal line.
I throw three dice and get 5, 3 and 2. Add the scores on the three
dice. What do you get? Now multiply the scores. What do you notice?
Complete the magic square using the numbers 1 to 25 once each. Each
row, column and diagonal adds up to 65.
Can you work out some different ways to balance this equation?
Suppose we allow ourselves to use three numbers less than 10 and
multiply them together. How many different products can you find?
How do you know you've got them all?
Got It game for an adult and child. How can you play so that you know you will always win?
Follow the clues to find the mystery number.
Have a go at balancing this equation. Can you find different ways of doing it?
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?
"Ip dip sky blue! Who's 'it'? It's you!" Where would you position yourself so that you are 'it' if there are two players? Three players ...?
What do the numbers shaded in blue on this hundred square have in common? What do you notice about the pink numbers? How about the shaded numbers in the other squares?
Explain why the arithmetic sequence 1, 14, 27, 40, ... contains many terms of the form 222...2 where only the digit 2 appears.
When Charlie asked his grandmother how old she is, he didn't get a
straightforward reply! Can you work out how old she is?
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
How many integers between 1 and 1200 are NOT multiples of any of
the numbers 2, 3 or 5?
A game for 2 people using a pack of cards Turn over 2 cards and try
to make an odd number or a multiple of 3.
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
Imagine a wheel with different markings painted on it at regular
intervals. Can you predict the colour of the 18th mark? The 100th
A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.
The number 8888...88M9999...99 is divisible by 7 and it starts with
the digit 8 repeated 50 times and ends with the digit 9 repeated 50
times. What is the value of the digit M?
The sum of the first 'n' natural numbers is a 3 digit number in which all the digits are the same. How many numbers have been summed?
Find the highest power of 11 that will divide into 1000! exactly.