It's 8.30am and Bournville Junior School is a hive of activity. The bell may not have rung yet but pupils are already hard at work – running their own shop selling second hand uniforms.

The entrepreneurial Year Six students are diligently pricing up stock and discussing possible new ways to market the new store.

And while the shop is not only helping parents to save cash on pricey uniforms, it is also boosting the pupil's maths and literacy skills as they master the art of stock control, advertising, pricing and finance management.

More than 30 ten and 11-year-olds have volunteered to staff the shop in an old store cupboard five days a week.

The shop is the brainchild of Bournville Schools PTA – a charity run by parents of pupils at both the infant and junior schools, which sit side by side on Linden Road in the heart of the village created by chocolate pioneer George Cadbury.

Alongside the uniforms, pupils have been selling DVDs of school productions, Christmas and birthday cards, wrapping paper and gift tags.

Pupil Scarlett Rea, aged 11, said: "It has been interesting to learn so much about how a shop works, from designing our own adverts and working out our staff rota to learning more about money and customer service.

"We are really pleased that it has been a success and we've worked really hard as a team."

David Roberts, chairman of the PTA, said the shop had already proved a hit – raising £200 in its first two weeks of operation, money which will be ploughed into making a creative space in the junior school's playground.

"The shop serves many purposes," he added. "While the children get to experience real life enterprise and gain vital business skills in customer service, time keeping, handling money and team work, our parents now have access to great quality uniform and the PTA gets a very visible focal point to do even more exciting projects from."

And the PTA, like hundreds up and down the country, is proving to be an indispensable resource for the schools.

As the Government squeezes its budget, schools in Britain are finding themselves having to come with innovative ways to increase funding – including seeking the help of parents and PTAs.

Over the last three years, Bournville Schools PTA has raised more than £30,000, money that has been used by both schools to fund resources for classrooms or to improve facilities for pupils, including converting a single decker bus into a learning space for the infants.

But the PTA is about much more than raising cash, added Mr Roberts.

"PTAs are often an overlooked vehicle for making exciting and new things happen in schools," he said. "As a parent, you tend to find that you have a longer relationship with your children's school than most other organisations in your life.

"There are always untapped skills, experience and willingness in the parent base that can make the learning environment an even better place.

"Helping the school shop get off the ground, for example, is just one way that we are creating new opportunities for these new skills to be gained."

Mr Roberts added: "I think we will see PTAs take an even more active role in delivering local services in the future – after all, who's to say that they can't employ people to address a market need with a highly localised service? It's only tradition that states that they have to be entirely volunteer led."