Can you each work out the number on your card? What do you notice? How could you sort the cards?

Can you hang weights in the right place to make the equaliser balance?

Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?

Choose four of the numbers from 1 to 9 to put in the squares so that the differences between joined squares are odd.

Use the interactivities to fill in these Carroll diagrams. How do you know where to place the numbers?

Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?

Can you draw a continuous line through 16 numbers on this grid so that the total of the numbers you pass through is as high as possible?

Place the numbers from 1 to 9 in the squares below so that the difference between joined squares is odd. How many different ways can you do this?

How have the numbers been placed in this Carroll diagram? Which labels would you put on each row and column?

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?

There are nasty versions of this dice game but we'll start with the nice ones...

As you come down the ladders of the Tall Tower you collect useful spells. Which way should you go to collect the most spells?

Fill in the numbers to make the sum of each row, column and diagonal equal to 15.

Move from the START to the FINISH by moving across or down to the next square. Can you find a route to make these totals?

Fill in the numbers to make the sum of each row, column and diagonal equal to 34. For an extra challenge try the huge American Flag magic square.

Cassandra, David and Lachlan are brothers and sisters. They range in age between 1 year and 14 years. Can you figure out their exact ages from the clues?

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.

In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?

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.

On Planet Plex, there are only 6 hours in the day. Can you answer these questions about how Arog the Alien spends his day?

This activity is best done with a whole class or in a large group. Can you match the cards? What happens when you add pairs of the numbers together?

Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.

Place the digits 1 to 9 into the circles so that each side of the triangle adds to the same total.

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.

Twizzle, a female giraffe, needs transporting to another zoo. Which route will give the fastest journey?

Can you make a train the same length as Laura's but using three differently coloured rods? Is there only one way of doing it?

Find your way through the grid starting at 2 and following these operations. What number do you end on?

These caterpillars have 16 parts. What different shapes do they make if each part lies in the small squares of a 4 by 4 square?

Can you see why 2 by 2 could be 5? Can you predict what 2 by 10 will be?

The clockmaker's wife cut up his birthday cake to look like a clock face. Can you work out who received each piece?

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?

Place this "worm" on the 100 square and find the total of the four squares it covers. Keeping its head in the same place, what other totals can you make?

Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.

Make your own double-sided magic square. But can you complete both sides once you've made the pieces?

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

Use these head, body and leg pieces to make Robot Monsters which are different heights.

This task, written for the National Young Mathematicians' Award 2016, involves open-topped boxes made with interlocking cubes. Explore the number of units of paint that are needed to cover the boxes. . . .

Number problems at primary level that require careful consideration.

Fill in the missing numbers so that adding each pair of corner numbers gives you the number between them (in the box).

Use the information about Sally and her brother to find out how many children there are in the Brown family.

Make one big triangle so the numbers that touch on the small triangles add to 10. You could use the interactivity to help you.

There were 22 legs creeping across the web. How many flies? How many spiders?

In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?

In this calculation, the box represents a missing digit. What could the digit be? What would the solution be in each case?

Woof is a big dog. Yap is a little dog. Emma has 16 dog biscuits to give to the two dogs. She gave Woof 4 more biscuits than Yap. How many biscuits did each dog get?