Exploring and noticing

problem
Favourite

How tall?

Age

5 to 11

Challenge level

A group of children are discussing the height of a tall tree. How would you go about finding out its height?
game

Strike it out for two

Age

5 to 11

Challenge level

Strike it Out game for an adult and child. Can you stop your partner from being able to go?
problem
Favourite

Digit addition

Age

5 to 11

Challenge level

Try out this number trick. What happens with different starting numbers? What do you notice?
problem

Counting stick conjectures

Age

5 to 11

Challenge level

How many rectangles can you see? Are they all the same size? Can you predict how many rectangles there will be in counting sticks of different lengths?
problem

Month mania

Age

5 to 11

Challenge level

Can you design a new shape for the twenty-eight squares and arrange the numbers in a logical way? What patterns do you notice?
problem

Taking a die for a walk

Age

5 to 11

Challenge level

Investigate the numbers that come up on a die as you roll it in the direction of north, south, east and west, without going over the path it's already made.
problem

Train carriages

Age

5 to 11

Challenge level

Suppose there is a train with 24 carriages which are going to be put together to make up some new trains. Can you find all the ways that this can be done?
problem

Four colours

Age

5 to 11

Challenge level

Kate has eight multilink cubes. She has two red ones, two yellow, two green and two blue. She wants to fit them together to make a cube so that each colour shows on each face just once.
problem
Favourite

Make 37

Age

5 to 11

Challenge level

Four bags contain a large number of 1s, 3s, 5s and 7s. Can you pick any ten numbers from the bags so that their total is 37?
problem
Favourite

Hundred square

Age

5 to 11

Challenge level

A hundred square has been printed on both sides of a piece of paper. What is on the back of 100? 58? 23? 19?