Choose a symbol to put into the number sentence. Starting with
the number 180, take away 9 again and again, joining up the dots
as you go. Watch out - don't join all the dots! Can you see why
2 by 2 could be 5? Can you predict what 2 by 10 Can you make a
cycle of pairs that add to make a square number using all the
numbers in the box below, once and once only? Place six toy
ladybirds into the box so that there are two ladybirds in every
column and every row. Choose four of the numbers from 1 to 9 to
put in the squares so that the differences between joined
squares are odd. Place the numbers 1 to 10 in the circles so
that each number is the difference between the two numbers just
below it. Start by putting one million (1 000 000) into the
display of your calculator. Can you reduce this to 7 using just
the 7 key and add, subtract, multiply, divide and equals as many
times as you like? Place the numbers 1 to 6 in the circles so
that each number is the difference between the two numbers just
below it. Imagine a p