Researchers have found that more than a quarter of children aged between 10 and 12 can't add together two small sums of cash without the aid of a calculator.
The study - undertaken by online tuition service, Mytutor, also found that many children were leaving primary school unable to do their times tables or spell.
The study found that a whopping third of kids cannot do division or basic algebra, whilst half have no idea what a noun is and cannot identify an adverb. Around a third cannot use apostrophes correctly.
The study revealed some shocking shortcomings in kids' mathematical abilities, with 27 per cent unable to add £2.36 and £1.49 to get £3.85, more than a third (36 per cent) unable to divide 415 by five, and a quarter not knowing the correct answer to seven multiplied by six!
Nick Smith, head of online tuition at Mytutor, told The Mirror: "Maths and English are key skills for children as they enter secondary school, yet our study shows that many are already slipping behind their peers and could be lacking confidence."
He said that addressing learning issues early can make an enormous difference to a child's school life:
"Hectic modern lifestyles are leaving parents with less and less time to spend learning with their children - whether that is helping with homework or other educational activities.
"Many think that their child's learning is suffering as a result, yet fewer than one in 10 of the parents we asked had used private tuition to give their children a boost to their learning."
Almost half of the parents polled said they thought their child's mathematical abilities were worse than theirs at the same age, whilst more than a third said the same about their child's English.
Almost four in 10 parents (39 per cent) admitted they spent less time helping their kids with their schoolwork than their own parents had, with 59 per cent saying they spent less than an hour a week - or eight-and-a-half minutes a day.
Wow, those breakdowns look scary!
Do you think you spend more time on learning activities with your children than that? Or do you just run out of the time at the end of the day for those sorts of things?