What are the rules of precedence for maths. e.g. how to solve 4 plus 4 plus 508 take away 12 forward slash 20 times 4 forward slash 100?

Answer 1

This type of problem is easy if broken down into chunks by following some basic rules in which the order of the operators (add, multiply etc) is carried out in strict order.

The key is to remember in which order the operators must be made. To help, use the acronymn BODMAS means:

Brackets ( ) or [ ] or { }

Other: meaning things like squaring (42), cubing (63), roots etc.

Divide /

Multiply x

Addition +

Subtraction -

Taking the problem 4 + 4 + 508 - 12 / 20 x 4 / 100

Solution:

You need to be careful because 4 + 4 + 508 - 12 really means (4 + 4 + 508 -12)

Also 20 x 4 really means (20 x 4)

So the actual problem must be rewritten first. It becomes:

(4 + 4 + 508 - 12) / (20x4) / 100

So now do the claculation using the BODMAS rule:

Brackets first.

(4 + 4 + 508 - 12). Inside the brackets do the Addition first.

4 + 4 + 508 = 516. Next Subtraction

516 - 12 = 504

Now do the same for (20 x 4) = 80

That's all the brackets done. There is no Other to worry about so move on to Division:

Using the answers above rewrite the problem again:

504 / 80 / 100

It matters not which order to do the division but the 80 /100 looks easiest.

80 / 100 = 0.8

rewrite the problem again, it now becomes:

504 / 0.8 = 630

The final answer is 630