Addition and subtraction

problem
Arrange the digits

Age

11 to 14

Challenge level

Can you arrange the digits 1,2,3,4,5,6,7,8,9 into three 3-digit numbers such that their total is close to 1500?
problem
Jugs of wine

Age

11 to 14

Challenge level

You have four jugs of 9, 7, 4 and 2 litres capacity. The 9 litre jug is full of wine, the others are empty. Can you divide the wine into three equal quantities?
problem
Clocked

Age

11 to 14

Challenge level

Is it possible to rearrange the numbers 1,2......12 around a clock face in such a way that every two numbers in adjacent positions differ by any of 3, 4 or 5 hours?
problem
Constellation Sudoku

Age

14 to 18

Challenge level

Special clue numbers related to the difference between numbers in two adjacent cells and values of the stars in the "constellation" make this a doubly interesting problem.
problem
Pole star Sudoku 2

Age

11 to 16

Challenge level

This Sudoku, based on differences. Using the one clue number can you find the solution?
problem
Pros and cons

Age

14 to 16

Challenge level

If p is a positive integer and q is a negative integer, which of these expressions is the greatest?
problem
No square sums

Age

14 to 16

Challenge level

How many numbers do you need to remove to avoid making a perfect square?
problem
Rolling along the trail

Age

11 to 14

Challenge level

What could be the scores from five throws of this dice?
problem
Football sum

Age

11 to 14

Challenge level

Find the values of the nine letters in the sum: FOOT + BALL = GAME
problem
Napier's bones

Age

7 to 11

Challenge level

The Scot, John Napier, invented these strips about 400 years ago to help calculate multiplication and division. Can you work out how to use Napier's bones to find the answer to these multiplications?