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43
Combined
Operations
UNIT
6
Objectives
Information in this unit will enable you to:
Recognize when you need to use more than one type of operation to solve a
math problem.
Describe the order in which the operations should be performed based on the
specifi cs of the problem.
Problems Involving More Than One Type
of Operation
Many of the math problems you will encounter in the machine shop will require you
to use a combination of addition, subtraction, multiplication, and division. For example,
you might have to add several lengths of bar stock, subtract another length, then
multiply the results to fi nd the weight.
Example 6-1
You draw the following lengths of bar stock from the supply room: 2 pieces at
48 inches, 3 pieces at 60 inches, and 1 piece that was 72 inches before someone
cut 24 inches off from it. If the bar stock weighs 3 pounds (48 ounces) per foot,
and it costs 3 dollars per pound, what is the cost of the bar stock you will use?
Step 1: Add all lengths
48″
48″
60″
60″
60″
+ 72″

348
(Continued)
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