Dame Rachel de Souza said girls do not give up on maths because the subject is too difficult and said some of the best young mathematicians she has met have been girls.
It come after Katharine Birbalsingh, head of Michaela Community School in Wembley, prompted anger by saying girls do not choose physics A-Level because they dislike “hard maths.”
Ms Birbalsingh, who is the government’s social mobility commissioner, made the comments to MPs at a science and technology committee inquiry.
Dame Rachel, who on Wednesday launched a website encouraging young people to study maths, said: “I think we have to break this idea Maths is ‘too difficult’. It is a fantastic subject.”
She added: “I have seen in my 30 years as an educator before becoming Commissioner that girls can be put off maths, not because it was ‘hard’, but far more because they weren’t encouraged the subject ‘was for them’.
“This must change, some girls were the best young mathematicians I’ve seen.”
To mark National Numeracy Day today, Dame Rachel published dozens of career profiles of inspirational people who use maths in their jobs, as part of a ‘Where Can I Go With Maths’ online quiz.
Children can type in which area of maths they enjoy and they are then shown profiles of people who mention how that area of maths is used in their work.
Dame Rachel said: “I am committed to getting the best from pupils whoever they are and whatever their background. I want to encourage all children to pursue STEM subjects.”
She added: “I am passionate about the importance of Maths and STEM subjects for all pupils – boys and girls. I want all pupils to feel they can choose them and be able to do their very best in these subjects.”
The department for education also on Wednesday launched an online quiz for adults to encourage them to think about whether they need help with maths. Participants answer six maths questions and are given information about where they can get support with improving their skills.
A spokesman for the department for education said around 17 million adults in England have the numeracy skills of primary school children, which can hold them back in work.
He added that the quiz is part of the government’s commitment to help more people get a good job, grow the economy and tackle the cost of living.