A mathematical clown and friends have set a new world record by building a 23ft pyramid made entirely out of balloons.

Caroline Ainslie, of Fortess Road, Kentish Town, constructed the giant Sierpinski pyramid with fellow “pyraloons” at Cambridge Science Festival earlier this month.

The 52-year-old helped build the pyramid dressed as her alter-ego Bubbles the Mathematical Clown to raise funds for charity the African Institute of Mathematical Sciences Schools Enrichment Centre (AIMSSEC), which helps train students and teachers in rural towns and villages in Africa.

Ms Ainslie runs Bubbly Maths, an educational organisation which tours primary schools worldwide delivering workshops that aim to make maths fun and accessible.

She said: “The biggest problem in Africa is mathematical education, that’s what’s really holding them back.

“Students who get to university will fail their first year because they don’t have the maths grounding. It’s absolutely tragic.”

Ms Ainslie built the pyramid, named after Polish mathematician Wacla Sierpinski, as part of a team of 15 at the Grafton Centre in Cambridge.

The challenge took place over two days between March 14 and 15 and required 2,048 balloons.

Ms Ainslie explained: “On the Friday, we inflated about 1,000 balloons. Two balloons make one pyramid and the fractal shape we were making is made up of 1,024 small pyramids.”

It took Ms Ainslie and her team about 10 hours to construct the pyramid and they are now preparing to officially register it with Guinness World Records as it is believed to be the largest Sierpinski pyramid ever made.

The team raised £225 on the day towards bursaries to fund teacher training for African students through AIMSSEC.

Ms Ainslie added: “We had a lot of technical problems because of balloons popping. The building had a glass roof so we had a greenhouse effect.

“When we finished at 4pm, a huge cheer went up. We had a lovely big crowd. We felt such relief.”

If you wish to donate to AIMSSEC, visit www.givengain.com/activist/34783/projects/4204/