Factors and multiples

problem
Surprising split

Age

7 to 11

Challenge level

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

Age

7 to 11

Challenge level

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

Age

7 to 11

Challenge level

Complete the Mathdoku grid using the clues. Can you convince us that the number you have chosen for each square has to be correct?
problem
Digit discovery

Age

7 to 11

Challenge level

Here is an interesting property about two sets of digits. Can you work out what the digits might be?
problem
Pebbles

Age

7 to 11

Challenge level

Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?
problem
It figures

Age

7 to 11

Challenge level

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?
problem
Round and round the circle

Age

7 to 11

Challenge level

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.
problem
Neighbours

Age

7 to 11

Challenge level

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?
problem
What two ...?

Age

7 to 11

Challenge level

56 406 is the product of two consecutive numbers. What are these two numbers?
problem
Spelling circle

Age

7 to 11

Challenge level

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