Jack and the 99p shop

Our elder daughter, Catherine, her husband, Carl, and their two boys, Luke and Jack, have moved in with us for six months, while their new house is being built. Well, it's proving to be an interesting logistical exercise, running our two different patterns of living side by side, but so far we're managing and enjoying it!

It's great having the two grandsons here, of course. Now, I know you all think there's nothing more tedious than grandparents going on about how wonderful their grandchildren are, but, too bad, that won't stop me.

Luke is 13, in Year 8 at high school. When he turned up here last week he immediately got busy setting up all the family's technology – it's all way beyond me! It's comforting to know that I have a resident IT expert to call on to sort out all my computing problems for the next six months.

Jack is 9, in Year 5 at junior school. It is, of course, a real treat for me to engage with his mathematics! He's clearly very able in this subject: not just in conventional mathematics attainment, but also in terms of creative ability in mathematics. Here's a little example of his creative thinking.

At the breakfast table, Granny was talking to Catherine about the local 99p store – where each item costs 99p. Jack listened attentively and then commented: 'That means if you buy 99 things and pay a pound each for them, then you would have enough change to buy another one!'

Now that's not hard maths, but it's an original insight. What is impressive is that Jack came up with this as an independent observation, not in response to a question that that an adult had posed. This ability to pose your own interesting and original questions about a mathematical situation is one of the key indicators in my construct of mathematical creativity.

Jack went on to show the ability to formulate generalisations. 'What if there were a 98p shop and you bought 98 things, paying a pound for each one?' I asked. Immediately came the response: 'Then you would have enough change to buy two more things.' And then, unprompted, he went on: 'And if you had a 97p shop and bought 97 things, you could but three more things. And in a 96p shop, four more things ...'

You must agree that's first rate mathematical thinking for a 9-year-old! I think I'm going to enjoy these six months.