The Grade One maths problem most adults can't solve.

How’s your maths at this point in your life?

Could you complete primary school level equations? Perhaps even a few high school ones, too?

Great, then try this one.

A family in the US, The Holderness Family, took to their family Facebook page to share their six-year-old’s maths homework after being totally baffled upon reading it for themselves.

“Internet friends: solve this 1st grade math homework,” they wrote, accompanied by an image of the problem itself.

The post, which has since been liked more than 2,000 times and with just as many comments, has left Facebook users stumped as to how the question should be answered and why it was set out for six year olds in the first place.

“FYI, this was the final page on a 7 page sheet, the previous 6 pages were a much more normal level for a first grader. I don’t think the teacher expects everyone to get this, I think it was meant to be a problem that would challenge the children, so for that reason I think it’s great that our school included it,” they acknowledged under the photo.

It didn’t help many-a-confused parent try to nut the problem out.

“I’m 40 and my brain cannot bend in these ways,” one commented.

“What the heck? I am not smarter than a first grader,” another pointed out.

However, one dogged user, Heather Combs Dutton decided to settle the confusion once and for all.

While I agree this is too advanced for a 1st grader (my 7-year-old niece would not understand this complexity at all!); I still had to solve it,” she wrote alongside her solution

“You add diagonally and subtract across and down to get the missing number of 14,” she added.

Therefore, the answer is J = 14.

Because duh, that’s what I was thinking all along?