Addition and subtraction

problem

Scoring With Dice

Age

7 to 11

Challenge level

I throw three dice and get 5, 3 and 2. Add the scores on the three dice. What do you get? Now multiply the scores. What do you notice?
problem

Seven Square Numbers

Age

7 to 11

Challenge level

Add the sum of the squares of four numbers between 10 and 20 to the sum of the squares of three numbers less than 6 to make the square of another, larger, number.
problem

Marvellous Matrix

Age

7 to 11

Challenge level

Follow the directions for circling numbers in the matrix. Add all the circled numbers together. Note your answer. Try again with a different starting number. What do you notice?
problem

Rod Measures

Age

7 to 11

Challenge level

Using 3 rods of integer lengths, none longer than 10 units and not using any rod more than once, you can measure all the lengths in whole units from 1 to 10 units. How many ways can you do this?
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

Some Secret Codes

Age

7 to 11

Challenge level

Can you follow the rule to decode the messages?
game

Nice or Nasty for Two

Age

7 to 14

Challenge level

Some Games That May Be Nice or Nasty for an adult and child. Use your knowledge of place value to beat your opponent.
problem

Charitable Pennies

Age

7 to 14

Challenge level

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

3 by 3 Mathdokus

Age

7 to 14

Challenge level

Can you use the clues to complete these 3 by 3 Mathematical Sudokus?
problem

Escape From the Castle

Age

7 to 14

Challenge level

Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?