One day someone stuck a dart in her hand and she whacked it straight into the dead centre of the bullseye. She went tenpin bowling for the first time at the age of 86, again with no clue about technique, and knocked over all 10 pins on her fifth turn.
The great attraction of these games is that they offer the primeval excitement of hunting for prey, without the need to harm any living creature.
They also give an opportunity for children to develop their understanding of mathematical concepts in a natural way. The more sophisticated can even get excited about the gentle parabola of a dart's flight.
All of which leads me to congratulate the education minister who attended the world darts championship to cement a formal link between the sport and education. Should ministers be busy on the day, by the way, I shall be available to represent the DfES at this year's FA Cup Final (purely in the interest of mathematics, of course: goalkeepers narrowing the angle, keeping score, counting up spectators).
Although we do better in international comparisons in mathematics than used to be the case, we are still not especially brilliant at number. Only in innumerate Britain could a numeracy hour last as little as 45 minutes.
A DfES spokesman said about darts: "Some fans may struggle with the rapid mental arithmetic required to keep up with the sport. Others may not realise that their skill with mental arithmetic when playing darts could stand them in good stead if they returned to the classroom."
Fair enough. I can imagine that reception class teachers, if they took up darts, might find it easier to work out how many tickboxes they had filled in for each five-year-old in their class. In all they have to complete 117 items, or "treble 19, single 20, double top", as we say in the darts world.
The good news is that primary children are now better at handling numbers than was the case a few years ago. The bad news is that every numeracy hour, like Caesar's Gaul, is divided into three parts. Repeated and predictable lesson patterns, especially in the years leading up to Sats, are killing what for many children is a natural fascination with mathematics.
Our daily world teems with mathematics, as we are surrounded, not just by manifestations of number, but by shapes, spaces, dimensions, relationships, predictions, odds and probabilities. The curriculum development work over many years by my Exeter colleague, Professor David Burghes, is full of engaging examples of the mathematics of everyday life.
What is more, children are quite clever at addressing problems in an intuitive way. In very early childhood they are able to devise their own equivalents of plus and minus, for example, before they ever meet these formal notions in school.
In some countries there are uneducated street children who can do complex calculations in their head. Sadly it is often to do with drug peddling or other illegal activities.
I can remember the son of a bookmaker who could calculate complex odds, because he helped his dad. Or the coal merchant's son, rapidly working out the cost of several bags of this and that. Both were bereft in the more formal setting of school maths.
So ministers' encouragement of links between school maths and the everyday world is to be welcomed. It challenges the imagination, beats off the diet of dreary repetitions, and capitalises on children's natural ways of observing, deducing and learning. It is also very enjoyable.
It is a little known fact that the new secretary of state is leading this push for more interesting and meaningful mathematics.
When she was appointed there was some misreporting about her, suggesting that she came from a private school background and belonged to a little-known religious group, but I can now reveal the truth.
As a Bolton Wanderers fan Ruth Kelly must, ipso facto, be a traditional northern working- class Labour politician. Her name is Elsie Ramsbottom, former pupil of Eebygum community college, and she is not a member of Opus Dei, but rather of Hopus Dei (pronounced without the "H" in the north).
"Hopus" is clearly the Latin word for hops, so the northern group 'opus Dei must be dedicated to the drinking of real ale.
Look out for our Elsie down at the Dog and Duck, doing her bit to support interesting ways of learning mathematics by counting up the number of customers ordering a pint of Old Peculiar.