ORDER OF OPERATIONS

Here you have a video explaining the Order of operations. In Engish it's called PEMDAS:

So that, remember: when you have a mathematical expression, you have to follow this order:

1. Parentheses,
2. Exponents,
3. Multiplications and Divisions
4. Additions and Substractions

Don´t worry if you don´t understand all the words, the most important thing is to understand the general idea!!