Ben’s Cat

Ben’s cat has splashed milk on these sums!

Can you finish them for him?

Put a + or a - sign where each I is.

1) 5 I 4I 3 I 2 I 1 = 5 2) 7 I 2 I 3 I 4I 5 = 5 3) 6 I 4 I 1 I 5 I 3 = 5 4) 7 I 5 I 4 I 3 I 8 = 5 5) 2 I 9 I 3 I 4 I 1 = 5

Brain teasers from page 44

6-8 Solutions

1) 5 + 4 - 3 - 2 + 1 = 5 2) 7 + 2 - 3 + 4 - 5 = 5 3) 6 - 4 + 1 + 5 - 3 = 5 4) 7 + 5 + 4 - 3 - 8 = 5 5) 2 + 9 - 3 - 4 + 1 = 5 Extensions It is easy to make up more problems like these.

Simply write down a calculation then remove the operation signs.

Problems could involve fewer numbers or more numbers.

8-11 Solutions Pirate Pete dug up 24 gold coins and 60 rubies. He gave two gold coins to the look-out and 15 rubies to the mate.

Note: These problems are based one one written 1,400 years ago by the great Indian mathematician Brahmagupta. Pupils can make up similar puzzles for others to solve.