When the pupils of Humbie Primary failed to win a prize in the annual CowParade Edinburgh competition, they were undaunted.
"We want a real cow - not an ornament," was their response.
After all, the 20-pupil school is set in a farming community in rural East Lothian, where real cows are part of children's everyday life. So head Therese Laing agreed - the school would buy a calf. But the purchase would become a central part of its numeracy and enterprise strategy for the eight pupils in the P4-7 class. Pupils would have to find out how much it cost to buy a calf, and factor in the cost of food and vets' bills.
As Humbie teacher Mhairi Stratton told a recent national numeracy conference, held by Learning and Teaching Scotland in Edinburgh, the class had to calculate how long they could afford to keep a cow.
Farmer Sandy Hodge, whose farm Humbie Mill is about half a mile from the school, agreed to help out. He was about to buy some calves from Tarporley, near Liverpool, and said he would let the school buy one at cost price.
This presented another opportunity for maths in context: how far was it from Humbie to Tarporley? How many stops would the farmer have to make on his drive? How long would it take him to get there?
Mr Hodge returned with his load of calves, and the class had to choose which one to buy. Every calf was different, so they had to base their decision on various criteria: would their calf be raised as a breeding heifer, or slaughtered for beef?
The class chose Holly, using Pounds 140 of the school's enterprise money. Mr Hodge agreed to look after Holly along with the rest of his herd, for a fee. The children had to calculate the food bills, which grew as Holly grew in weight. How many sacks of feed would Holly need?
Then the day came when Holly had to be sold. "It's a business," explained Mrs Stratton, an idea that the children accepted quite unsentimentally.
In the end, they sold her back to Mr Hodge for Pounds 730, but only Pounds 371.50 of that was clear profit after bills for food and veterinary treatment. The farmer has kept her as a breeding heifer and, as The TESS went to print, Holly's calf was due any day, much to the pupils' excitement.
Mrs Stratton believes the project has had real impact. The pupils have learnt about profit and risks, taking hard decisions for the long term and that there is a genuine purpose to learning mathematical skills.