You've probably had your fair share of puzzling maths questions that your child has presented to you.
Here it goes...
All you have to do is fill in the gaps with the digits from one to nine, so that the equation makes sense.
Translated from the VN Express, teacher Tran Phuong explains you have to follow this order of operations: multiply first, then divide, then addition and then subtract.
Tran Phuong told the VN Express: “This problem is difficult even for adults good at math, so it will be difficult for students in grades three."
He said that he had sent the problem to some people who have degrees in economics and they still have not given him an answer.
Although the question requires simple basic arithmetic, it's completely puzzling parents. And teachers. And everyone else.
In the PISA tables, which rank students' performance throughout the world, Vietnam ranks 17 in maths, whereas the UK ranks 26.
So, can you solve it?
Seriously, can you?