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# Basic Math/help

Question
Hello Sir

Sir Our Maths teacher told that addition and multiplication goes parallel and Subtraction and division goes parallel . Sir Please explain the meaning  in detail according to my age is 14 yrs 10 months 10 days.

Sir i request please dont reply that it outside of my expertise.

Thankyou

Hello Aishwarya,

I am guessing your teacher means by "parallel" that they have the same priority
when performing the operations.  However, that is not true.  There is an abbreviation
we use, I hope it was introduced to you, called PEMDAS... which gives the correct
order of operations.  It represents:
Parentheses
Exponents
Multiplication
Division
Subtraction

Which means, when simplifying expressions, we first do the parentheses, followed
by exponents, then multiplication and division (from left to right), then addition and
subtraction (in either order).

So, the only true "parallel" operations are addition and subtraction.  Multiplication and
division are too, but they get performed from "left to right."  Some examples, where I use
"/" for division and "*" for multiplication:
1. 10-2*3+8/4 = 10-6+2 = 4+2 = 6
2. 12/6*2 = (12/6)*2 = 2*2 = 4, NOT 12/(6*2) = 12/12 = 1...the correct answer is 4 (not 1).

See now?

For more, here some website that should help.
http://www.mathgoodies.com/lessons/vol7/order_operations.html#
http://www.purplemath.com/modules/orderops.htm

I hope this helps.

A. Mantell

Basic Math

Volunteer

#### Abe Mantell

##### Expertise

Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!

##### Experience

Over 15 years teaching at the college level.

Organizations belong to
NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.

Education/Credentials
B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook