Multiplication and division

problem
The genie in the jar

Age

11 to 14

Challenge level

This jar used to hold perfumed oil. It contained enough oil to fill granid silver bottles. Each bottle held enough to fill ozvik golden goblets and each goblet held enough to fill vaswik crystal spoons. Each day a spoonful was used to perfume the bath of a beautiful princess. For how many days did the whole jar last? The genie's master replied: Five hundred and ninety five days. What three numbers do the genie's words granid, ozvik and vaswik stand for?
problem
Largest product

Age

11 to 14

Challenge level

Which set of numbers that add to 100 have the largest product?
problem
Multiply the addition square

Age

11 to 14

Challenge level

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?
problem
Round and round and round

Age

11 to 14

Challenge level

Where will the point stop after it has turned through 30 000 degrees? I took out my calculator and typed 30 000 ÷ 360. How did this help?
problem
Debasing the coinage

Age

11 to 14

Challenge level

How much lighter will £5 worth of 5p's be with these new lighter coins?
problem
Multiples Sudoku

Age

11 to 14

Challenge level

Each clue in this Sudoku is the product of the two numbers in adjacent cells.
problem
Going round in circles

Age

11 to 14

Challenge level

Mathematicians are always looking for efficient methods for solving problems. How efficient can you be?
problem
Can you make 100?

Age

11 to 14

Challenge level

How many ways can you find to put in operation signs (+, −, ×, ÷) to make 100?
problem
Gabriel's problem

Age

11 to 14

Challenge level

Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
problem
Same answer

Age

11 to 14

Challenge level

Aisha's division and subtraction calculations both gave the same answer! Can you find some more examples?