If you thought solving maths questions for year Five Chinese students was hard then you might want to have a look at this equation stumping the internet.
Facebook users are trying to grapple with this deceptively difficult problem posed to seven-year-old pupils in Australia.
Mother, Angie Warner was handed this question by her Year Two daughter, with both struggling to come up with the correct solution.
Ms Warner then posted it to a parenting Facebook group where she appealed for help from other users.
The question reads: "There are 49 dogs signed up to compete in the dog show.
"There are 36 more small dogs than large dogs signed up to compete. How many small dogs are signed up to compete?"
Think you've got the answer? Well, it may not be as clear-cut as you think.
If you answered 13 large dogs and 39 small dogs then you are on the wrong track, thanks to the composition of the question.
Thankfully, one modest maths genius has come up with the correct answer - all thanks to the power of algebra.
Here's how to solve the problem - *Warning spoilers*
First, you need to divide the animals into sets: x for large dogs, and y for small dogs
49 = x+y and y = x+36
49 = x + x+36
49 = 2x+36
13 = 2x
x = 6.5
y = 42.5
Therefore the amount of small dogs is 42.5 meaning the result is, confusingly, not a whole number.
Ms Warner later explained: "The district worded it wrong. The answer would be 42.5, though, if done at an age-appropriate grade."