Oders of Operations
There are a lot of post on social media discussing about this topic, but the rule is just PEMDAS from left to right.
- Parenthesis - Perform operations inside the parenthesis.
- Exponents - Perform exponents if there are exponents, do not create exponents for the sake of having an operation "E" . If there are exponents given then use the operation, if not this does not mean we need to rewrite numbers interms of exponents so that we can use "exponent".
- Example: 100 x 10 x 5 ÷ 3: We do not write 103 x 5 ÷ 3, so that we could use E from PEMDAS. Since there is no exponent on the original problem then we just proceed from multiplication to division.
- Multiplication or Division - Perform multiplication or division what ever comes first from left to right.
- Addition or Subtraction - Perform addition or subtraction what ever comes first from left to right.
Note: In a single digit 2(3), this means 2 x 3. The parenthesis may be changed to multiplication sign.
Here is a PEMDAS flow chart
Examples:
- Here is an example similar to a familar problem on facebook: 25÷5(2 + 3 ). Is the answer 25 or 1? Lets analyze.
- Inside the parenthesis: 25÷5(5)
- 25÷5x5: Since () denotes multiplication
- 5x5: Division from left to right
- 25: Answer
- Some of the comments said there that, there should be an "E" (exponent) before division or multiplication, here is the argument.
- Inside the parenthesis: 25÷5(5)
- 25÷5x5: Since () denotes multiplication
- 25÷52: Since 5x5 = 52. Yeah it is true that 5x5 = 52, but under the rule it did not say rewrite - it is perform, so this step is wrong. We should perform what is in there.
- 25÷25: Division from left to right
- 1: Answer