It is never too young to start thinking about running a business or managing money.
At least two pre-schools, Dreamkids and Cherie Hearts - which has a chain of 25 centres here - have made it part of their curriculum to teach such skills, The Straits Times has learnt.
Children learn things such as how wares are sold or how to buy goods at a supermarket, which also teaches communication and independence.
They are taught values such as prudence - understanding that money has to be earned and spent wisely - and generosity.
Said Dreamkids' vice-principal and teacher Jocelyn Goh, 38: "The world is changing and new jobs require 21st-century skills such as problem-solving and creativity.
"As entrepreneurship is part of today's economy, we believe that by teaching the younger generation about it, they will believe they too can shape the world, young as they are, and we give them the courage, innovation skills and curiosity to do so."
At Dreamkids, pre-schoolers attend entrepreneurship classes 30 minutes a day, for four to six weeks, and have weekly financial literacy classes.
The five- and six-year-olds will be raising funds for the first time by selling lemonade at Marine Cove at a future date, with all proceeds going to Alex's Lemonade Stand Foundation.
The idea was inspired by the late Alexandra Scott, an American victim of cancer who opened a lemonade stand to raise money to help other children with cancer despite her failing health. She died at the age of eight, and her parents set up a charity foundation in her name.
As part of the fund-raising, the children will learn about cancer and how the money they raise will help cancer patients.
After this fund-raiser, Dreamkids plans to get the children involved in selling donated toys, where their proceeds will go towards buying new toys for children with cancer - a plan that was suggested by the pre-schoolers themselves.
At Cherie Hearts, the centres organise events such as a half-day carnival where the children have to brainstorm ideas for items to sell and decide on their pricing. They also need to think of ways to record, count and tally the sales.
At the most recent carnival at Cherie Hearts @ Charlton (Kovan), the children set up 11 booths, including one for temporary tattoos and one for fishing games.
Said Ms Michelle Wong, K2 educator and coordinator for the Young Entrepreneurs' Day at Cherie Hearts @ Charlton: "Not only were the older children very excited to contribute things from home, but they were also eager to teach the younger ones how to decorate and wrap the items for sale. They also stayed patiently at their booths to sell and promote their products."
The carnival raised $4,135 for non-profit organisation Wings Counselling Centre, which offers counselling services to individuals, couples, families and children.
Along with these fund-raisers, Cherie Hearts also holds weekly financial literacy classes to teach pre-schoolers the value of money, using its own original textbooks.
Teachers said that despite their age, pre-schoolers are able to understand the meaning and purpose of entrepreneurship.
Said Ms Ong Yen Lyn, branch director of Cherie Hearts @ Upper Thomson: "The pre-schoolers can clearly understand the concepts taught. No adjustments to the curriculum are necessary, except to put the children's experience into perspective and deliver the lessons on financial literacy in context with what they are already familiar with.
"They enjoy behaving like adults with money who decide what they need and can buy, and are happy to put into practice what they have learnt during entrepreneurial events, and with their parents."
Ms Jasmine Xu, mother of Cherie Hearts @ Upper Thomson's K2 pupil Jastin Liu, six, said she was impressed by how children can display mature reasoning at a tender age.
She recalled that at a bookstore, Jastin grabbed a storybook and requested her to buy it for him.
She said: "When I asked if he really needed the book, he hesitated and looked across at the library opposite the bookstore, then told me he could borrow the book from the library instead of buying it."