Having problems with a condition

Hello, I have created a function to set the rotation for my actor. The function is called by pressing a key and the rotation changes in 15, 30, 45.
Since I can move my actor releasing the key too, I want to evaluate if the rotation value at the moment is one of the default values (15, 30 or 45)
I am using the Division function in order to get the remainder value. If the remainder is 0, the cannon rotation is one of the default values, but Unreal says that the value is not in scope and, actually the condition is never true. Here is my blueprint