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?
Number problems at primary level that may require determination.
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?
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?
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?
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?
There are ten children in Becky's group. Can you find a set of numbers for each of them? Are there any other sets?
How many different sets of numbers with at least four members can you find in the numbers in this box?
Got It game for an adult and child. How can you play so that you know you will always win?
What is the lowest number which always leaves a remainder of 1 when divided by each of the numbers from 2 to 10?
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?
Work out Tom's number from the answers he gives his friend. He will only answer 'yes' or 'no'.
Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?
Number problems at primary level to work on with others.
Can you work out what a ziffle is on the planet Zargon?
This article for teachers describes how number arrays can be a useful reprentation for many number concepts.
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?
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
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.
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?
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?
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?
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?
56 406 is the product of two consecutive numbers. What are these two numbers?
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?
Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?
Find the words hidden inside each of the circles by counting around a certain number of spaces to find each letter in turn.
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?
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.
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.
Look at three 'next door neighbours' amongst the counting numbers. Add them together. What do you notice?
"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 ...?
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?
Are these statements always true, sometimes true or never true?
Have a go at balancing this equation. Can you find different ways of doing it?
Investigate the sum of the numbers on the top and bottom faces of a line of three dice. What do you notice?
When Charlie asked his grandmother how old she is, he didn't get a straightforward reply! Can you work out how old she is?
How can you use just one weighing to find out which box contains the lighter ten coins out of the ten boxes?
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.
These red, yellow and blue spinners were each spun 45 times in total. Can you work out which numbers are on each spinner?
An investigation that gives you the opportunity to make and justify predictions.
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?
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?
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.
Follow the clues to find the mystery number.
Does a graph of the triangular numbers cross a graph of the six times table? If so, where? Will a graph of the square numbers cross the times table too?