Multiplication and division

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?
problem

Sometimes We Lose Things

Age

7 to 11

Challenge level

Well now, what would happen if we lost all the nines in our number system? Have a go at writing the numbers out in this way and have a look at the multiplications table.
problem

The 24 Game

Age

7 to 11

Challenge level

There are over sixty different ways of making 24 by adding, subtracting, multiplying and dividing all four numbers 4, 6, 6 and 8 (using each number only once). How many can you find?
problem

Sam's Quick Sum

Age

7 to 11

Challenge level

What is the sum of all the three digit whole numbers?
problem

ABC

Age

7 to 11

Challenge level

In the multiplication calculation, some of the digits have been replaced by letters and others by asterisks. Can you reconstruct the original multiplication?
problem

Practice Run

Age

7 to 11

Challenge level

Chandrika was practising a long distance run. Can you work out how long the race was from the information?
problem

Divide It Out

Age

7 to 11

Challenge level

What is the lowest number which always leaves a remainder of 1 when divided by each of the numbers from 2 to 10?
problem

One Million to Seven

Age

7 to 11

Challenge level

Start by putting one million (1 000 000) into the display of your calculator. Can you reduce this to 7 using just the 7 key and add, subtract, multiply, divide and equals as many times as you like?
problem

A First Product Sudoku

Age

7 to 14

Challenge level

Given the products of adjacent cells, can you complete this Sudoku?
problem

Charitable Pennies

Age

7 to 14

Challenge level

Investigate the different ways that fifteen schools could have given money in a charity fundraiser.