Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
It's easy to work out the areas of most squares that we meet, but what if they were tilted?
A 750 ml bottle of concentrated orange squash is enough to make fifteen 250 ml glasses of diluted orange drink. How much water is needed to make 10 litres of this drink?
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
Can you recreate squares and rhombuses if you are only given a side or a diagonal?
Stuart's watch loses two minutes every hour. Adam's watch gains one minute every hour. Use the information to work out what time (the real time) they arrived at the airport.
Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.
