Addition and subtraction

problem

Sending Cards

Age

7 to 11

Challenge level

1 out of 3

This challenge asks you to investigate the total number of cards that would be sent if four children send one to all three others. How many would be sent if there were five children? Six?
problem

It's All About 64

Age

7 to 11

Challenge level

1 out of 3

Write the numbers up to 64 in an interesting way so that the shape they make at the end is interesting, different, more exciting ... than just a square.
problem

Christmas Shopping

Age

7 to 11

Challenge level

1 out of 3

Vera is shopping at a market with these coins in her purse. Which things could she give exactly the right amount for?
problem

Calendar Patterns

Age

7 to 11

Challenge level

1 out of 3

In this section from a calendar, put a square box around the 1st, 2nd, 8th and 9th. Add all the pairs of numbers. What do you notice about the answers?
problem

Super Value Shapes

Age

7 to 11

Challenge level

1 out of 3

If each of these three shapes has a value, can you find the totals of the combinations? Perhaps you can use the shapes to make the given totals?
problem

Page Numbers

Age

7 to 11

Challenge level

1 out of 3

Exactly 195 digits have been used to number the pages in a book. How many pages does the book have?
problem

Clever Keys

Age

7 to 11

Challenge level

1 out of 3

On a calculator, make 15 by using only the 2 key and any of the four operations keys. How many ways can you find to do it?
problem

Oranges and Lemons

Age

7 to 11

Challenge level

1 out of 3

On the table there is a pile of oranges and lemons that weighs exactly one kilogram. Using the information, can you work out how many lemons there are?
problem

Back to School

Age

7 to 11

Challenge level

1 out of 3

Mr. Sunshine tells the children they will have 2 hours of homework. After several calculations, Harry says he hasn't got time to do this homework. Can you see where his reasoning is wrong?
problem

Dividing a Cake

Age

7 to 11

Challenge level

1 out of 3

Annie cut this numbered cake into 3 pieces with 3 cuts so that the numbers on each piece added to the same total. Where were the cuts and what fraction of the whole cake was each piece?