An Australian mother has been left perplexed by maths homework given to her young daughter - and after sharing the question on social media, she realised she's not the only one.
Angie Werner took a photo of the question and posted it on a Facebook group, discovering in the process that the Year 2 equation (Year 3 in New Zealand) was not as easy as it first seemed.
"There are 49 dogs signed up to compete in the dog show," it began.
"There are 36 more small dogs than large dogs signed up to compete. How many small dogs are signed up to compete?"
The error that most are likely to make initially is to simply subtract 36 from 49 to get 13 large dogs, an error because the difference between 36 and 13 is actually 23, not 36.
Warning: answer below.
Try and work it out yourself before seeing the answer, but if you're truly stumped here's how you work it out.
The reality is, the answer's a little bit fishy, because it deals with fractions of dogs - a sight you'd only be greeted with at some sort of dystopian dog show.
The only possible answer is 6.5 large dogs, and 42.5 small dogs. That's the only way you get 36 more small dogs than large and get them adding up to 49.
So there you go! If our collective struggle for an answer is any indication, we definitely need to brush up on our arithmetic.