Section 4: Arithmetic Operations

When performing a series of arithmetic operations (i.e. addition, subtraction, division, multiplication, exponents), you must perform those operations in a particular order. There is a mnemonic to help you remember the order – PEMDAS:

P Parentheses
E Exponents
M Multiplication
D Division
A Addition
S Subtraction

If you have a series of operations, do what’s in parentheses first, then apply exponents, then do any multiplication or division, and finally do any adding or subtracting.


Image of a series of operations

Do what’s in parentheses first (find LCD):

Image showing 2 minus 1/4

So now we have

Image showing what 3 multiplied by the fraction 7/4 looks like

Now apply exponents:

Image showing what 2 cubed looks like

So now we have 

Image showing an operation consisting of 4+3 multiplied by the fraction 7/4 (this in in parenthesis) minus 8

So now we have

Image showing 4 plus the fraction 21/4 minus 8

Now do addition and subtraction (find LCD):

Image showing the additional and subtraction of fractions. 16/4 plus 21/4 - 32/4 equals 5/4

So our answer is 

Image of the fraction 5/4

Take Order of Arithmetic Operations Assessment
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