Andrew decorated 20 biscuits to take to a party. He lined them up and put icing on every second biscuit and different decorations on other biscuits. How many biscuits weren't decorated?
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?
Find the words hidden inside each of the circles by counting around
a certain number of spaces to find each letter in turn.
Which pairs of cogs let the coloured tooth touch every tooth on the
other cog? Which pairs do not let this happen? Why?
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.
What happens when you turn these cogs? Investigate the differences
between turning two cogs of different sizes and two cogs which are
If you count from 1 to 20 and clap more loudly on the numbers in
the two times table, as well as saying those numbers loudly, which
numbers will be loud?