If you ever doubted it, then this week the government made it quite clear. The teaching of maths is important. After a swathe of reports where disbelieving journalists discovered that to get a grade A in GSCE maths, you didn’t actually need to answer any of the hardest questions, the Qualifications and Curriculum Authority (QCA) has announced that next September, it is introducing a new, two-tier arrangement for GCSE maths.

The QCA says this will not only test “the most able candidates . . . to the maximum capacity”, but ensure that those graded at A or A* have indeed answered questions up to that level. There is also going to be a further maths GCSE.

Some parents will receive this news with relief. After all, if your child is at a top-performing school, it must be rather galling if the exams are wildly below the standards of that school. Others will be worried, since maths is one of those perennial classroom issues that many schools would rather fudge than attack with vigour.

A third group of parents might feel rather smug. I’m talking about those of us who sit their children down every afternoon, open a yellow plastic pouch and get to grips with the mysteries of addition, subtraction and the rest. This, to the unaware, is the heart of Kumon maths. In thousands of households across the UK, the phrase “Have you done your Kumon?” has become a familiar daily cry. In our home, we did Kumon on Christmas Day. This is not weird, it’s just part of the Kumon Way.

Kumon started in the UK in 1991 but was created in Japan by Toru Kumon, a maths teacher, in 1954. Concerned that his young son was falling behind in arithmetic, he started devising work sheets for him. Since then Kumon has spread worldwide in its two subject areas, maths and the language native to a particular country. Globally, 3.7m children are taking classes. There are more than 500 Kumon franchises in Britain alone.

It is quite cultish. Parents have to promise to ensure their sprogs do it every day, and also to mark the sheets themselves. And with its special files and folders, individualised homework and aspiration to perfection, Kumon is quite deliberately removed from the experience of ordinary school.

Yet it works. Last summer we went away for half term with another family. My eight-year-old daughter Phoebe was impressed when her best friend, also eight, and a Kumon pupil, revealed she could fluently recite her times tables up to 12. Peer pressure did its thing. “Please let me do Kumon,” she begged. Funny things, children.

It then appeared everyone’s child was doing Kumon. One friend whose child could not read at nine attested that the only thing which achieved the much-desired “literacy breakthrough” was her Kumon English worksheet. Phoebe is now doing maths and English, and after a lot of begging, her brother Gabriel is also doing maths.

Your child must aim to do the daily worksheet in less than 10 minutes. No working-out, or rubbing-out, is allowed. The parent then marks the paper. Any mistakes are circled, and the child tries again. And again, until the right answer is reached. This delivers the sought-after 100% mark. When your child regularly achieves 100% in 10 minutes, he or she moves up a grade. Each subject costs £45 a term.

Carol Brenner runs the Islington Kumon centre which has 130 children in regular attendance. Her husband Lester runs the neighbouring centre at Stoke Newington, with 80 kids per week. Apparently, parents are terrible cheats. “It doesn’t fool me,” says Brenner, “because I mark them properly and time them in class. And there are never any mistakes in the English papers, which is a dead giveaway.”

Doing something skilled without a teacher around might be part of the draw, although as a parent, facing a pamphlet full of arithmetic every day is a not entirely welcome addition. Fiona Abrahams’s son Matthew, 8, has been doing Kumon maths for nearly four years. “It’s not that he goes to a bad school; he’s at a very good C of E school in north London, but it has built his confidence,” she says. “He knows all his times tables far better than me . . . Ten minutes a day is enough. And I use the marking book to help me!”

Of course, Kumon appears the perfect thing for parents wishing to bolt on another weapon of attack in the hideously competitive educational arena. It’s a cheaper version of hiring the tutor, now positioned as a solemn duty any loving parent ignores at their peril. How many parents have total assurance that the school they have chosen will equip their child for their next educational stage? Particularly now that maths GCSE is getting harder.

Parental confidence has been shaken, and educational additions, particularly for the under-11s, are now an unstoppable force. This one at least has the side effect of getting parents to brush up on their tables.