A game in which players take it in turns to choose a number. Can you block your opponent?
Sequences of multiples keep cropping up...
Do you know a quick way to check if a number is a multiple of two? How about three, four or six?
Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
A country has decided to have just two different coins, 3z and 5z
coins. Which totals can be made? Is there a largest total that
cannot be made? How do you know?
The clues for this Sudoku are the product of the numbers in adjacent squares.
Imagine we have four bags containing a large number of 1s, 4s, 7s and 10s. What numbers can we make?
Using your knowledge of the properties of numbers, can you fill all the squares on the board?
Follow this recipe for sieving numbers and see what interesting patterns emerge.
Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...
Can you describe this route to infinity? Where will the arrows take you next?
Powers of numbers behave in surprising ways. Take a look at some of these and try to explain why they are true.
Can you find a relationship between the number of dots on the
circle and the number of steps that will ensure that all points are
In this problem, we have created a pattern from smaller and smaller
squares. If we carried on the pattern forever, what proportion of
the image would be coloured blue?
Can you create a Latin Square from multiples of a six digit number?
Is there an efficient way to work out how many factors a large number has?
Can you guarantee that, for any three numbers you choose, the
product of their differences will always be an even number?
Some 4 digit numbers can be written as the product of a 3 digit
number and a 2 digit number using the digits 1 to 9 each once and
only once. The number 4396 can be written as just such a product.
Can you find the factors?
This article takes the reader through divisibility tests and how they work. An article to read with pencil and paper to hand.
Is there a relationship between the coordinates of the endpoints of a line and the number of grid squares it crosses?
Caroline and James pick sets of five numbers. Charlie chooses three of them that add together to make a multiple of three. Can they stop him?
What is the largest number which, when divided into 1905, 2587,
3951, 7020 and 8725 in turn, leaves the same remainder each time?
Which numbers can we write as a sum of square numbers?