What i have learnt this week

I have learnt this week in maths what is the right one of these symbols  + - X  and the division symbol to work out a question like this 45 - 32 =

This is how you work out that question.

You don't - the 2 on the 32 you just - 30

Then you - the answer to 45 - 30 = 15

So you - the 15 - 2 = 13 and that's your answer.