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?
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?
Is it possible to draw a 5-pointed star without taking your pencil
off the paper? Is it possible to draw a 6-pointed star in the same
way without taking your pen off?
Are these statements always true, sometimes true or never true?
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?
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 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?
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
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?
This article for teachers describes how number arrays can be a
useful reprentation for many number concepts.
What is the lowest number which always leaves a remainder of 1 when
divided by each of the numbers from 2 to 10?
56 406 is the product of two consecutive numbers. What are these
Number problems at primary level that may require determination.
Can you work out what a ziffle is on the planet Zargon?
Look at three 'next door neighbours' amongst the counting numbers. Add them together. What do you notice?
Work out Tom's number from the answers he gives his friend. He will
only answer 'yes' or 'no'.
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?
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.
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?
These red, yellow and blue spinners were each spun 45 times in
total. Can you work out which numbers are on each spinner?
Investigate the sum of the numbers on the top and bottom faces of a line of three dice. What do you notice?
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?
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.
Number problems at primary level to work on with others.
Explore the relationship between simple linear functions and their
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?
An investigation that gives you the opportunity to make and justify
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?
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.
The planet of Vuvv has seven moons. Can you work out how long it is
between each super-eclipse?
Andrew decorated 20 biscuits to take to a party. He lined them up and put icing on every second biscuit and different decorations on other biscuits. How many biscuits weren't decorated?
Starting with the number 180, take away 9 again and again, joining up the dots as you go. Watch out - don't join all the dots!
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
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.
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?
I am thinking of three sets of numbers less than 101. Can you find
all the numbers in each set from these clues?
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?
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?
Have a go at balancing this equation. Can you find different ways of doing it?
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?
If you have only four weights, where could you place them in order
to balance this equaliser?
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?
A three digit number abc is always divisible by 7 when 2a+3b+c is divisible by 7. Why?
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?
Find the words hidden inside each of the circles by counting around
a certain number of spaces to find each letter in turn.
How can you use just one weighing to find out which box contains
the lighter ten coins out of the ten boxes?
Can you find any perfect numbers? Read this article to find out more...
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?