Introducing algebra

problem
Sisters and brothers

Age

7 to 11

Challenge level

Cassandra, David and Lachlan are brothers and sisters. They range in age between 1 year and 14 years. Can you figure out their exact ages from the clues?
problem
Think of two numbers

Age

11 to 14

Challenge level

Think of two whole numbers under 10, and follow the steps. I can work out both your numbers very quickly. How?
problem
Buckets of thinking

Age

7 to 11

Challenge level

There are three buckets each of which holds a maximum of 5 litres. Use the clues to work out how much liquid there is in each bucket.
problem
Plenty of pens

Age

7 to 11

Challenge level

Amy's mum had given her £2.50 to spend. She bought four times as many pens as pencils and was given 40p change. How many of each did she buy?
problem
Augustus' age

Age

7 to 11

Challenge level

In 1871 a mathematician called Augustus De Morgan died. De Morgan made a puzzling statement about his age. Can you discover which year De Morgan was born in?
problem
Spell by numbers

Age

7 to 11

Challenge level

Can you substitute numbers for the letters in these sums?
problem
Super shapes

Age

7 to 11

Challenge level

The value of the circle changes in each of the following problems. Can you discover its value in each problem?
problem
How many eggs?

Age

7 to 11

Challenge level

Peter, Melanie, Amil and Jack received a total of 38 chocolate eggs. Use the information to work out how many eggs each person had.
problem
Heads and feet

Age

5 to 7

Challenge level

On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?
problem
Two and two

Age

7 to 16

Challenge level

How many solutions can you find to this sum? Each of the different letters stands for a different number.