List

Multiplication and Division

Abundant Numbers
problem
Favourite

Abundant Numbers

Age
7 to 11
Challenge level
filled star empty star empty star
48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?
A Square of Numbers
problem
Favourite

A Square of Numbers

Age
7 to 11
Challenge level
filled star empty star empty star
Can you put the numbers 1 to 8 into the circles so that the four calculations are correct?
How do you do it?
problem
Favourite

How do you do it?

Age
7 to 11
Challenge level
filled star empty star empty star

This group activity will encourage you to share calculation strategies and to think about which strategy might be the most efficient.

Picture Your Method
problem
Favourite

Picture Your Method

Age
7 to 11
Challenge level
filled star empty star empty star
Can you match these calculation methods to their visual representations?
Odd Squares
problem
Favourite

Odd Squares

Age
7 to 11
Challenge level
filled star empty star empty star

Think of a number, square it and subtract your starting number. Is the number you're left with odd or even? How do the images help to explain this?

Compare the Calculations
problem
Favourite

Compare the Calculations

Age
7 to 11
Challenge level
filled star empty star empty star
Can you put these four calculations into order of difficulty? How did you decide?
Flashing Lights
problem
Favourite

Flashing Lights

Age
7 to 11
Challenge level
filled star empty star empty star
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?
Up and Down Staircases
problem
Favourite

Up and Down Staircases

Age
7 to 11
Challenge level
filled star empty star empty star
One block is needed to make an up-and-down staircase, with one step up and one step down. How many blocks would be needed to build an up-and-down staircase with 5 steps up and 5 steps down?
4 by 4 Mathdokus
problem
Favourite

4 by 4 Mathdokus

Age
7 to 14
Challenge level
filled star empty star empty star
Can you use the clues to complete these 4 by 4 Mathematical Sudokus?
Xavi's T-shirt
problem
Favourite

Xavi's T-shirt

Age
7 to 16
Challenge level
filled star empty star empty star

How much can you read into a T-shirt?

The Moons of Vuvv
problem
Favourite

The Moons of Vuvv

Age
7 to 11
Challenge level
filled star empty star empty star
The planet of Vuvv has seven moons. Can you work out how long it is between each super-eclipse?
Carrying Cards
problem
Favourite

Carrying Cards

Age
7 to 11
Challenge level
filled star empty star empty star
These sixteen children are standing in four lines of four, one behind the other. They are each holding a card with a number on it. Can you work out the missing numbers?
An Easy Way to Multiply by 10?
problem
Favourite

An Easy Way to Multiply by 10?

Age
7 to 11
Challenge level
filled star empty star empty star
Do you agree with Badger's statements? Is Badger's reasoning 'watertight'? Why or why not?
Follow the numbers
problem
Favourite

Follow the numbers

Age
7 to 11
Challenge level
filled star empty star empty star

What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.

Music to my Ears
problem
Favourite

Music to my Ears

Age
7 to 11
Challenge level
filled star empty star empty star
Can you predict when you'll be clapping and when you'll be clicking if you start this rhythm? How about when a friend begins a new rhythm at the same time?
Journeys in Numberland
problem
Favourite

Journeys in Numberland

Age
7 to 11
Challenge level
filled star empty star empty star

Tom and Ben visited Numberland. Use the maps to work out the number of points each of their routes scores.

Multiplication Squares
problem
Favourite

Multiplication Squares

Age
7 to 11
Challenge level
filled star empty star empty star

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.

What's in the Box?
problem
Favourite

What's in the Box?

Age
7 to 11
Challenge level
filled star empty star empty star

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?

Factors and Multiples Game
game
Favourite

Factors and Multiples Game

A game in which players take it in turns to choose a number. Can you block your opponent?

Ordering cards
problem
Favourite

Ordering cards

Age
5 to 11
Challenge level
filled star empty star empty star
This problem is designed to help children to learn, and to use, the two and three times tables.
Dicey Array
game
Favourite

Dicey Array

Watch the video of this game being played. Can you work out the rules? Which dice totals are good to get, and why?

Let us divide!
problem
Favourite

Let us divide!

Age
7 to 11
Challenge level
filled star empty star empty star
Look at different ways of dividing things. What do they mean? How might you show them in a picture, with things, with numbers and symbols?
Shape Times Shape
problem
Favourite

Shape Times Shape

Age
7 to 11
Challenge level
filled star empty star empty star
These eleven shapes each stand for a different number. Can you use the number sentences to work out what they are?
Multiply Multiples 1
problem
Favourite

Multiply Multiples 1

Age
7 to 11
Challenge level
filled star empty star empty star
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
Sweets in a box
problem
Favourite

Sweets in a box

Age
7 to 11
Challenge level
filled star empty star empty star

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?

Multiply Multiples 2
problem
Favourite

Multiply Multiples 2

Age
7 to 11
Challenge level
filled star empty star empty star
Can you work out some different ways to balance this equation?
What Do you Need?
problem
Favourite

What Do you Need?

Age
7 to 11
Challenge level
filled star empty star empty star
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?
Multiply Multiples 3
problem
Favourite

Multiply Multiples 3

Age
7 to 11
Challenge level
filled star empty star empty star
Have a go at balancing this equation. Can you find different ways of doing it?
Highest and Lowest
problem
Favourite

Highest and Lowest

Age
7 to 11
Challenge level
filled star empty star empty star
Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.
Which is quicker?
problem
Favourite

Which is quicker?

Age
7 to 11
Challenge level
filled star empty star empty star
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
Three Dice
problem
Favourite

Three Dice

Age
7 to 11
Challenge level
filled star empty star empty star
Investigate the sum of the numbers on the top and bottom faces of a line of three dice. What do you notice?
Division Rules
problem
Favourite

Division Rules

Age
7 to 11
Challenge level
filled star empty star empty star
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Zios and Zepts
problem
Favourite

Zios and Zepts

Age
7 to 11
Challenge level
filled star empty star empty star
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?
Trebling
problem
Favourite

Trebling

Age
7 to 11
Challenge level
filled star empty star empty star
Can you replace the letters with numbers? Is there only one solution in each case?
Times Tables Shifts
problem
Favourite

Times Tables Shifts

Age
7 to 11
Challenge level
filled star empty star empty star

In this activity, the computer chooses a times table and shifts it. Can you work out the table and the shift each time?

Make 100
problem
Favourite

Make 100

Age
7 to 11
Challenge level
filled star filled star empty star
Find at least one way to put in some operation signs to make these digits come to 100.
Table patterns go wild!
problem
Favourite

Table patterns go wild!

Age
7 to 11
Challenge level
filled star filled star empty star
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.
Counting Cogs
problem
Favourite

Counting Cogs

Age
7 to 14
Challenge level
filled star filled star empty star
Which pairs of cogs let the coloured tooth touch every tooth on the other cog? Which pairs do not let this happen? Why?
Light the Lights Again
problem
Favourite

Light the Lights Again

Age
7 to 11
Challenge level
filled star filled star empty star

Each light in this interactivity turns on according to a rule. What happens when you enter different numbers? Can you find the smallest number that lights up all four lights?

Mystery Matrix
problem
Favourite

Mystery Matrix

Age
7 to 11
Challenge level
filled star filled star empty star
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
Multiples Grid
problem
Favourite

Multiples Grid

Age
7 to 11
Challenge level
filled star filled star empty star

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?

One Wasn't Square
problem
Favourite

One Wasn't Square

Age
7 to 11
Challenge level
filled star filled star empty star
Mrs Morgan, the class's teacher, pinned numbers onto the backs of three children. Use the information to find out what the three numbers were.
All the Digits
problem
Favourite

All the Digits

Age
7 to 11
Challenge level
filled star filled star empty star
This multiplication uses each of the digits 0 - 9 once and once only. Using the information given, can you replace the stars in the calculation with figures?
Factor track
problem
Favourite

Factor track

Age
7 to 11
Challenge level
filled star filled star empty star
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.
Factor Lines
problem
Favourite

Factor Lines

Age
7 to 14
Challenge level
filled star filled star empty star
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Factor-Multiple Chains
problem
Favourite

Factor-Multiple Chains

Age
7 to 11
Challenge level
filled star filled star empty star
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?
Two Primes Make One Square
problem
Favourite

Two Primes Make One Square

Age
7 to 11
Challenge level
filled star filled star empty star
Can you make square numbers by adding two prime numbers together?
Four Go
problem
Favourite

Four Go

Age
7 to 11
Challenge level
filled star filled star empty star
This challenge is a game for two players. Choose two of the numbers to multiply or divide, then mark your answer on the number line. Can you get four in a row?
Pebbles
problem
Favourite

Pebbles

Age
7 to 11
Challenge level
filled star filled star empty star

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?

Cycling Squares
problem
Favourite

Cycling Squares

Age
7 to 11
Challenge level
filled star filled star empty star
Can you make a cycle of pairs that add to make a square number using all the numbers in the box below, once and once only?
Picture a Pyramid ...
problem
Favourite

Picture a Pyramid

Age
7 to 11
Challenge level
filled star filled star empty star

Imagine a pyramid which is built in square layers of small cubes. If we number the cubes from the top, starting with 1, can you picture which cubes are directly below this first cube?

Round and round the circle
problem
Favourite

Round and round the circle

Age
7 to 11
Challenge level
filled star filled star empty star

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.

Remainders
problem
Favourite

Remainders

Age
7 to 14
Challenge level
filled star filled star empty star
I'm thinking of a number. My number is both a multiple of 5 and a multiple of 6. What could my number be?
Four goodness sake
problem
Favourite

Four goodness sake

Age
7 to 11
Challenge level
filled star filled star filled star

Use 4 four times with simple operations so that you get the answer 12. Can you make 15, 16 and 17 too?

Curious number
problem
Favourite

Curious number

Age
7 to 11
Challenge level
filled star filled star filled star

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?

So it's times!
problem
Favourite

So it's times!

Age
7 to 14
Challenge level
filled star filled star filled star

How will you decide which way of flipping over and/or turning the grid will give you the highest total?

Cubes within Cubes
problem
Favourite

Cubes within Cubes

Age
7 to 14
Challenge level
filled star filled star filled star

We start with one yellow cube and build around it to make a 3x3x3 cube with red cubes. Then we build around that red cube with blue cubes and so on. How many cubes of each colour have we used?