Evaluate seven plus eight times
five minus four.
Before we can evaluate this type of
expression, we need to think about what we know about order of operations. When we deal with expressions that
contain more than one operation, we use this order, the order of operations, to tell
us how to solve.
We start with parentheses then
exponents then multiplication and division from left to right, followed by addition
and subtraction from left to right. In our problem, we have two sets of
parentheses. We solve what’s inside the
parentheses for both of these problems.
First, seven plus eight equals
15. And then five minus four equals
one. We bring down the multiplication
symbol. Now that we finished our
parentheses step — there are no exponents in this problem — we can go ahead and
multiply 15 times one. 15 times one equals 15. Seven plus eight times five minus
four equals 15.