Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?

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

Find the words hidden inside each of the circles by counting around a certain number of spaces to find each letter in turn.

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?

Can you complete this jigsaw of the multiplication square?

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

Imagine a wheel with different markings painted on it at regular intervals. Can you predict the colour of the 18th mark? The 100th mark?

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.

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.

If you have only four weights, where could you place them in order to balance this equaliser?

In this maze of hexagons, you start in the centre at 0. The next hexagon must be a multiple of 2 and the next a multiple of 5. What are the possible paths you could take?

Play this game and see if you can figure out the computer's chosen number.

Find the squares that Froggie skips onto to get to the pumpkin patch. She starts on 3 and finishes on 30, but she lands only on a square that has a number 3 more than the square she skips from.

Kimie and Sebastian were making sticks from interlocking cubes and lining them up. Can they make their lines the same length? Can they make any other lines?

Can you sort numbers into sets? Can you give each set a name?

Ben and his mum are planting garlic. Use the interactivity to help you find out how many cloves of garlic they might have had.

I am thinking of three sets of numbers less than 101. Can you find all the numbers in each set from these clues?

How will you work out which numbers have been used to create this multiplication square?

Can you see how these factor-multiple chains work? Find the chain which contains the smallest possible numbers. How about the largest possible numbers?

Number problems at primary level to work on with others.

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?

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?

If there is a ring of six chairs and thirty children must either sit on a chair or stand behind one, how many children will be behind each chair?

Arrange any number of counters from these 18 on the grid to make a rectangle. What numbers of counters make rectangles? How many different rectangles can you make with each number of counters?

Does this 'trick' for calculating multiples of 11 always work? Why or why not?

How many trains can you make which are the same length as Matt's and Katie's, using rods that are identical?

Benâ€™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?

In a square in which the houses are evenly spaced, numbers 3 and 10 are opposite each other. What is the smallest and what is the largest possible number of houses in the square?

Investigate the smallest number of moves it takes to turn these mats upside-down if you can only turn exactly three at a time.

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?

How can you use just one weighing to find out which box contains the lighter ten coins out of the ten boxes?

Yasmin and Zach have some bears to share. Which numbers of bears can they share so that there are none left over?

Frances and Rishi were given a bag of lollies. They shared them out evenly and had one left over. How many lollies could there have been in the bag?

This article for teachers describes how number arrays can be a useful representation for many number concepts.

Pat counts her sweets in different groups and both times she has some left over. How many sweets could she have had?

Can you find the chosen number from the grid using the clues?

These red, yellow and blue spinners were each spun 45 times in total. Can you work out which numbers are on each spinner?

One quarter of these coins are heads but when I turn over two coins, one third are heads. How many coins are there?

How many different rectangles can you make using this set of rods?

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?

Factors and Multiples game for an adult and child. How can you make sure you win this game?

Look at the squares in this problem. What does the next square look like? I draw a square with 81 little squares inside it. How long and how wide is my square?

Use this grid to shade the numbers in the way described. Which numbers do you have left? Do you know what they are called?

Can you work out how to balance this equaliser? You can put more than one weight on a hook.

Got It game for an adult and child. How can you play so that you know you will always win?

Can you help the children in Mrs Trimmer's class make different shapes out of a loop of string?