Having won a fortune on the National Lottery, Ruth Maddison, deputy head of an East Sussex primary school, is doing exactly what she pleases. She has gone back to work.

Forty-year-old Ruth and her husband Paul, a partner in a Hastings double- glazing company, became one of the wealthiest couples in Britain just under a fortnight ago when they picked up half of the country’s biggest lottery prize so far - Pounds 22,590,829.

But two days after taking part in a high-kicking Tiller Girls’ routine for the benefit of newspaper photographers and TV cameras, she returned to Denton county primary school in Newhaven, clutching her sandwich lunch and a box of celebratory cream cakes for colleagues in the staffroom.

That first attempt to pick up the reins of her old life proved abortive. With the press pack baying at the school gates, she had to slip out of the back entrance and disappear for a few days. But by Monday the pack was off chasing salacious stories about her husband’s business partner and co-winner, Mark Gardiner, and Ruth was able to put in a relatively normal 8am-5.30pm school day.

The obvious question is “Why did she bother?” Even if she and her husband blow Pounds 1 million on a few Ferraris and a new house - “I’d like a place in the country with lovely views over the Downs,” she said - they could earn Pounds 600,000 a year just by leaving the remaining Pounds 10m in the bank.

She is amused by such calculations, but not altogether impressed. Unlike most of us, she was not seduced by the lure of the lottery and has never bought a ticket herself. “To be honest, it is an obscene amount of money to win, but hopefully it won’t make any difference to my teaching career. I can’t think of a more satisfying, or stressful, job. It’s the contact with the children that I enjoy - they have been making all sorts of suggestions on what I should spend the money on, ranging from going to Australia to buying a new roof for the school pool. The knowledge that you are making a difference to their lives is also very important to me.”

Ruth, who has no children of her own, is still planning to do an MA course - her particular interest is special educational needs - and wants to be the head of a medium-sized primary one day.

“I have tried to tell the children that my values haven’t altered and that money doesn’t lead to any satisfaction in life,” she said. “I was happy with my life before, and therefore there is no reason to change.”

Ruth is, however, going to treat herself to singing lessons and will buy a computer. “Funnily enough, because we don’t have a computer at home I was actually working on the school’s computer on the Sunday morning that my husband phoned to say we had won the lottery. I had gone into school to produce a booklet for student teachers and I asked him if I could finish it before joining him. That may seem strange, but at the time I couldn’t really believe that we had won.”

There are no plans for an exotic summer holiday though. She and Paul, 43, still plan to have a short break in Scotland at the beginning of the holidays and in late August she will spend a long-planned weekend in Chester with a group of friends who have also turned 40 this year. Between the two trips she will be popping back to school to check on the progress of the school administration block extension that is being built this summer.

But what chance does she really have of staying on in her present job even if her delighted colleagues continue to help by responding to her changed circumstances in as low-key a manner as possible?

Sceptics will predict that it will prove impossible, but Ruth has been heartened to learn that Rodica Woodcock, a former school lab technician who won Pounds 2,072,220.80 on Littlewoods pools in October 1991, is now working as a volunteer special needs teacher in Tower Hamlets, and is a governor of her old school in Dulwich.

“Reading about Rodica’s experience helped because it showed me that it is possible to live a normal life after winning a lot of money,” she said. “Mind you, she gave up her full-time job. I hope to go one better than that.”

* In 1993, an American teacher, Leslie C Robins, won an even bigger lottery prize than the Maddisons’ - 75 million dollars. He and his girlfriend will not receive all the money until 2012, however, as it is being paid in 20 annual instalments.