In November, Liz was interviewed for an article on a parents' website about learning times tables. Read the article here.
The Scot, John Napier, invented these strips about 400 years ago to
help calculate multiplication and division. Can you work out how to
use Napier's bones to find the answer to these multiplications?
This article for teachers looks at how teachers can use problems from the NRICH site to help them teach division.
This problem is designed to help children to learn, and to use, the two and three times tables.
56 406 is the product of two consecutive numbers. What are these
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?
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 work out some different ways to balance this equation?
What is the sum of all the three digit whole numbers?
Can you complete this calculation by filling in the missing numbers? In how many different ways can you do it?
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
There are four equal weights on one side of the scale and an apple
on the other side. What can you say that is true about the apple
and the weights from the picture?
After training hard, these two children have improved their results. Can you work out the length or height of their first jumps?
Use 4 four times with simple operations so that you get the answer 12. Can you make 15, 16 and 17 too?
Find out what a Deca Tree is and then work out how many leaves
there will be after the woodcutter has cut off a trunk, a branch, a
twig and a leaf.
All the girls would like a puzzle each for Christmas and all the
boys would like a book each. Solve the riddle to find out how many
puzzles and books Santa left.
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?
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
48 is called an abundant number because it is less than the sum of
its factors (without itself). Can you find some more abundant
The triangles in these sets are similar - can you work out the
lengths of the sides which have question marks?
Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?
Rocco ran in a 200 m race for his class. Use the information to
find out how many runners there were in the race and what Rocco's
finishing position was.
Have a go at balancing this equation. Can you find different ways of doing it?
Resources to support understanding of multiplication and division through playing with number.
Here is a picnic that Petros and Michael are going to share equally. Can you tell us what each of them will have?
Using the numbers 1, 2, 3, 4 and 5 once and only once, and the
operations x and ÷ once and only once, what is the smallest
whole number you can make?
There are over sixty different ways of making 24 by adding,
subtracting, multiplying and dividing all four numbers 4, 6, 6 and
8 (using each number only once). How many can you find?
Take the number 6 469 693 230 and divide it by the first ten prime
numbers and you'll find the most beautiful, most magic of all
numbers. What is it?
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?
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?
Number problems at primary level that may require determination.
This challenge encourages you to explore dividing a three-digit number by a single-digit number.
Number problems at primary level that require careful consideration.
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
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?
EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.
Where can you draw a line on a clock face so that the numbers on
both sides have the same total?
Zumf makes spectacles for the residents of the planet Zargon, who
have either 3 eyes or 4 eyes. How many lenses will Zumf need to
make all the different orders for 9 families?
Can you arrange 5 different digits (from 0 - 9) in the cross in the
Grandma found her pie balanced on the scale with two weights and a
quarter of a pie. So how heavy was each pie?
On my calculator I divided one whole number by another whole number and got the answer 3.125 If the numbers are both under 50, what are they?
Using the statements, can you work out how many of each type of
rabbit there are in these pens?
Use the information to work out how many gifts there are in each
In this investigation, you are challenged to make mobile phone
numbers which are easy to remember. What happens if you make a
sequence adding 2 each time?
Chandrika was practising a long distance run. Can you work out how
long the race was from the information?
This number has 903 digits. What is the sum of all 903 digits?
Find at least one way to put in some operation signs (+ - x ÷)
to make these digits come to 100.
Use your logical reasoning to work out how many cows and how many
sheep there are in each field.
If the numbers 5, 7 and 4 go into this function machine, what
numbers will come out?