PRACTICE WITH ORDER OF OPERATIONS

LESSON READ-THROUGH
by Dr. Carol JVF Burns (website creator)
Follow along with the highlighted text while you listen!
 

The order that operations are to be performed (when not clearly identified)
is summarized with the following memory device:

Please   Excuse   My   Dear   Aunt   Sally    (PEMDAS)



In September 2017, this problem was floating around the web:

Here's the solution, with correct order of operations: $$ \begin{alignat}{2} &\cssId{s19}{1 + 1 + 1 + 1 + 11 + 1 + 1 + 1 + 11 + 1\times 0 + 1}&& \cr &\qquad\cssId{s20}{= 1 + 1 + 1 + 1 + 11 + 1 + 1 + 1 + 11 + (1\times 0) + 1} &\qquad&\cssId{s21}{\text{(the multiplication gets done first)}} \cr &\qquad\cssId{s22}{= 1 + 1 + 1 + 1 + 11 + 1 + 1 + 1 + 11 + 0 + 1}\cr &\qquad\cssId{s23}{= 30} \end{alignat} $$ If this doesn't make sense to you, try the following mental exercise on a shorter (but similar) problem: $1 + 2 \times 0 + 3$
1 2 0 3
$$ \cssId{s37}{1 + 2 \times 0 + 3} \ \ \cssId{s38}{=\ \ 1 + \overbrace{(2\times 0)}^{\text{strong guy wins}} + 3} \ \ \cssId{s39}{=\ \ 1 + 0 + 3} \ \ \cssId{s40}{=\ \ 4}$$
MORE EXAMPLES:
$\cssId{s42}{-1 + 3\times 5 - 2} \cssId{s43}{= -1 + (3\times 5) - 2} \cssId{s44}{= 12}$
$\cssId{s45}{2 - 10\div 5 + 3} \cssId{s46}{= 2 - \frac{10}{5} + 3} \cssId{s47}{= 3}$
Master the ideas from this section
by practicing the exercise at the bottom of this page.


When you're done practicing, move on to the optional section:
Laurel, Yanny, Cookies, Bananas, and Clocks


Or, move on to:
Taking PEMDAS Too Literally: Don't Make This Mistake!

 
 

Feel free to use a pencil and scrap paper to work these problems.
However, do not use your calculator!

Simplify:
    
(an even number, please)