# solving scientific notations and order of operations

please click link to get handout for scientific notation: https://docs.google.com/document/d/11cbrL2xDHLt6fVfczER8ajqLggwk08PytcopwiEY0H4/edit

***if you want to have the document print, you can copy it and then paste it on a new document (MS Word).

so how does it work in solving mathematical operations?

i’ve been doing some research on how you solve on longer mathematical sentence comprising not just addition and subtraction but also multiplication and division. and what i’ve found out was, i was right 😀 😛 .. well, anyways the calculator was quite right i think.

anyways so there are rules to follow when you’re solving something, and yup as usual you do follow the so called MDAS step.. but not much strictly multiplication first, because it will depend which came first as i was saying, and it’s either division or multiplication.

so the rules are:

1. First do all operations that lie inside parentheses.
2. Next, do any work with exponents or radicals.
3. Working from left to right, do all multiplication and division.
4. Finally, working from left to right, do all addition and subtraction.
so what does rule number three (3) mean?
Evaluate 9 – 5 ÷ (8 – 3) x 2 + 6 using the order of operations Solution:
 Step 1: 9 – 5 ÷ (8 – 3) x 2 + 6 = 9 – 5 ÷ 5 x 2 + 6 Parentheses Step 2: 9 – 5 ÷ 5 x 2 + 6 = 9 – 1 x 2 + 6 Division Step 3: 9 – 1 x 2 + 6 = 9 – 2 + 6 Multiplication Step 4: 9 – 2 + 6 = 7 + 6 Subtraction Step 5: 7 + 6 = 13 Addition
and how about rule number two (2) and four (4)?

Example 1 – Parenthesis

 Without Parenthesis With Parenthesis 8 – 7 + 3 = 1 + 3 = 4 8 – (7 + 3) = 8 – 10 = -2

Example 2

 Order of Operations Explanation 22 x 20/4 – 7 x 3 + 55 = Calculate the exponent 4 x 20/4 – 7 x 3 + 55 = 4 x 5 – 21 + 55 = OR 80/4 – 21 + 55 = (4 x 5 and 80/4 both = 20) Working from left to right, do all multiplications and divisions. When there are several of these operations in the same term, the order within the term doesn’t matter 20 – 21 + 55 = Add and subtract from left to right 54 The correct answer!
or basically if you want to see some justifications over your calculations, i think calculators are pretty quite handy. 🙂
References:
1. Remelito Dublin says: