Addition and subtraction

problem

Let's Face It

Age

7 to 11

Challenge level

3 out of 3

In this problem you have to place four by four magic squares on the faces of a cube so that along each edge of the cube the numbers match.
problem

The 24 Game

Age

7 to 11

Challenge level

3 out of 3

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

3 out of 3

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

Oddly

Age

7 to 11

Challenge level

3 out of 3

Find the sum of all three-digit numbers each of whose digits is odd.
problem

Difference

Age

7 to 11

Challenge level

3 out of 3

Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
problem

Pouring the Punch Drink

Age

7 to 11

Challenge level

3 out of 3

There are 4 jugs which hold 9 litres, 7 litres, 4 litres and 2 litres. Find a way to pour 9 litres of drink from one jug to another until you are left with exactly 3 litres in three of the jugs.
problem

Scoring With Dice

Age

7 to 11

Challenge level

3 out of 3

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

3 out of 3

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

3 out of 3

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

3 out of 3

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?