In that case, you need to know the rules about which operations to do first. In normal algebra, powers have a higher priority than multiplications and divisions; and these, in turn, have a higher priority than addition and subtraction.
The various operations within the expression are carried out using the order of operations: BIDMAS (UK) or PEMDAS (US).
There are different rules for different operations.
order of operations
Operations are almost always carried out in the order of their importance to the task at hand.
yes
The answer will not be the same if you do not follow the order of operations. PEMDAS is the way most people remember it. It tells you what to do first and you need to know this to do the problems correctly. If not, you will often have the wrong answer.
order of operations
It means that the calculator can follow the order of operations and do the order of operations for you but, you need to know how to do them on your own too.
You need to know it's functions and prices
Computer are built on the laws of mathematics and so Excel must follow them. There are set rules for the order of operations that must be followed to ensure calculations are done in a consistent way. See the related question below.
You memorize the rules that are considered standard.
In that case, you need to know the rules about which operations to do first. In normal algebra, powers have a higher priority than multiplications and divisions; and these, in turn, have a higher priority than addition and subtraction.
If you change the order of operations, you will get a different result. The person who wrote the expression had a specific order of operations in mind (using generally-accepted rules), so arbitrarily using some other order of operations is, quite simply, wrong.
The various operations within the expression are carried out using the order of operations: BIDMAS (UK) or PEMDAS (US).
There are different rules for different operations.
order of operations