There is something wrong with the equation below:
By just exchanging two squares at a time, find the equality with the least amount of exchange.
For example if this question is asked for below equation, you may find the solution with one time exchange:
the answer will be exchanging "+" and "9" which makes the equation correct as below:
FYI: Even though it is not a hint, all numbers are used only once. ($0,1,2,3,4,5,6,7,8,9$)
Hint: you only swap each square once for optimal clear solution.