PRACTICE WITH ORDER OF OPERATIONS

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: $$ \begin{alignat}{2} 1 + 1 + \,&1 +\, 1 + 11 + 1 + 1 + 1 + 11 + 1\times 0 + 1&& \cr &= 1 + 1 + 1 + 1 + 11 + 1 + 1 + 1 + 11 + (1\times 0) + 1 &\qquad&\text{(the multiplication gets done first)} \cr &= 1 + 1 + 1 + 1 + 11 + 1 + 1 + 1 + 11 + 0 + 1\cr &= 30 \end{alignat} $$ 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
$$1 + 2 \times 0 + 3 \ \ =\ \ 1 + \overbrace{(2\times 0)}^{\text{strong guy wins}} + 3 \ \ =\ \ 1 + 0 + 3 \ \ =\ \ 4$$
MORE EXAMPLES:
[beautiful math coming... please be patient] $-1 + 3\times 5 - 2 = -1 + (3\times 5) - 2 = 12$
[beautiful math coming... please be patient] $2 - 10\div 5 + 3 = 2 - \frac{10}{5} + 3 = 3$
Master the ideas from this section
by practicing the exercise at the bottom of this page.

When you're done practicing, move on to:
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)