Teacher Ben Waldram shows us how to get on the road to cracking code with these challenging but achievable maths activities that are also an excellent way of assessing speaking and listening.

Children love to crack codes; to be the breakers of a riddle or a hidden message; to unlock what was once locked. So too, do we. The sense of achievement in breaking something that, at first, seemed unbreakable, is an amazing feeling. It's also a great first step towards understanding algebra.

There are many ways of using letters and symbols in maths – simply: 6 x ? = 60. Children will quickly tell you that the blank or question mark is 10. However, replace the question mark with a letter (6 x N = 60) and they look at you bewildered. Why is that? Why does the addition of a letter confuse them? From speaking to children throughout Key Stage 2, they often mentioned that: ‘We don’t use letters in numeracy, letters are for literacy!’ and ‘Why have you put an N there? It’s 10.’