Mum baffled by 'impossible' maths homework of seven-year-old

A PARENT HAS TAKEN TO THE INTERNET TO ASK FOR HELP WITH THEIR SEVEN-YEAR-OLD'S MATHS HOMEWORK - BUT OTHERS CLAIMED THE ANSWER WAS 'OBVIOUS' 09:05, 21 May 2025 One of the more

frustrating elements of parenthood is attempting to assist your children with their school work, only to discover that you're also stumped by the questions. This was the case for one

baffled mother, who headed to Reddit to post an image from her primary school child's maths workbook. "My seven-year old's homework is making me question my sanity," she

admitted in the CasualUK subreddit. The puzzling fraction question asked her child to identify an error in a diagram depicting a whole number divided into eight eighths. The assignment

asked: "Eva is working out what fraction is shown on the number line. What mistake has Eva made?" A fellow Reddit user couldn't help but express their own irritation,

commenting: "What's up with asking a student to figure out what some other wrong person thinks? Why would you want them to spend time getting the wrong way to do something into

their head? "This seems more like an exercise for teachers." They continued their rant: "I don't think I even understand the question, did Eva put the 1/8 markers on

there? Is Eva just looking at that atrocity and supposed to work out what errors the creator of the number line made? It's not even clear to me 'what fraction is shown on the

number line' means. The number line shows more than one fraction." A second individual admitted: "I've seen a number of these kiddies' maths questions now and the

phrasing of the question is infuriating. It's makes more sense to write 'What fraction is shown by adjacent vertical lines with downward pointing arrow heads? What fraction is

shown on the number line?' Shown by what? 2 adjacent arrow lines? 3 lines? 4 lines? When I was a kid the maths questions were unambiguous." Nonetheless, there were those ready to

solve the conundrum, providing a welcome assist to the perplexed parent. A swarm of Redditors clarified that Eva had incorrectly used sevenths in place of eighths - given that there are

actually just seven spaces between the eight lines, reports the Mirror. One maths whizz said: "It's called the fencepost error and it's been written about for thousands of

years," and proceeded to hint at its historical significance, noting that: "The Romans needed to know about this so they could work out how many pillars to put around a

temple." Another shared: "A fencepost error (also known as an off-by-one error). Occurs in programming too many times. Imagine the 8 arrows are fence posts and the number line the

actual fence - with 7 sections. If the total fence is 1 unit long, then each of the 7 fence sections is 1/7 units long, not 1/8." Another Redditor joined in, adding: "Teaching a

valuable lesson here! 'Fencepost error', 'off by one error' whatever you call it this is a very good maths question and shows a child's ability to think." A

teacher concurred, shedding light on the educational value of such queries. "Standard question in maths," they remarked. "Helps the child to develop their further

understanding of the concept being taught, in this case fractions. Article continues below "Finding the mistake (in this case, the mistake is that Eva counted the lines instead of the

sections, so got 1/8 instead of 1/7) forces the child to think more logically about the problem being presented, rather than simply asking something along the lines of 'what fraction is

shown on the number line?' Source: primary school teacher."