126 Chapter 1 Whole Numbers
- MEETINGS The Rotary Club meets every
14 days and the Kiwanis Club meets every 21 days.
If both clubs have a meeting on the same day, in
how many more days will they again meet on the
same day? - FLOWERS A florist is making flower
arrangements for a 4th of July party. She has 32 red
carnations, 24 white carnations, and 16 blue
carnations. He wants each arrangement to be
identical.
a. What is the greatest number of arrangements
that he can make if every carnation is used?
b. How many of each type of carnation will be
used in each arrangement?
SECTION 1.9 Order of Operations
To evaluate (find the value of) expressions
that involve more than one operation, use the
order-of-operations rule.
Order of Operations
- Perform all calculations within
parentheses and other grouping symbols
following the order listed in Steps 2–4
below, working from the innermost pair of
grouping symbols to the outermost pair. - Evaluate all exponential expressions.
- Perform all multiplications and divisions
as they occur from left to right. - Perform all additions and subtractions as
they occur from left to right.
When grouping symbols have been removed,
repeat Steps 2–4 to complete the calculation.
If a fraction bar is present, evaluate the
expression above the bar (called the numerator)
and the expression below the bar (called the
denominator) separately. Then perform the
division indicated by the fraction bar, if possible.
DEFINITIONS AND CONCEPTS EXAMPLES
Evaluate:
Work within the innermostparentheses first and then within the
outermostbrackets.
Do the subtraction
within the
parentheses.
Evaluate the
exponential
expression within the
brackets:
Do the multiplication
within the brackets.
Do the subtraction
within the brackets.
Do the multiplication:
Do the addition.
Evaluate:
Evaluate the expressions above and below the fraction bar separately.
In the numerator, evaluate the exponential
expression. In the denominator, subtract.
In the numerator, add. In the denominator,
multiply.
5 Divide.
35
7
33 8
7(1514)
27 8
7(1)
33 8
7(1514)
31
3[7]21.
10 21
10 3[7]
10 3[169]
24 16.
10 3[163(3)]
10 3[2^4 3( 5 2 )] 10 3[2^4 3( 3 )]
10 3[2^4 3(52)]
The arithmetic mean,or average,of a set of
numbers is a value around which the values of
the numbers are grouped.
To find the mean (average)of a set of values,
divide the sum of the values by the number of
values.
Find the mean (average) of the test scores and 73.
Since there are 5
scores, divide by 5.
Do the addition in the numerator.
Divide.
The mean (average) test score is 80.
80
400
5
Mean