Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website.
9
UNIT
2
Adding Whole
Numbers
Objectives
After studying this unit, you will be able to:
▪
Practice methods used to add whole numbers.
▪
Demonstrate carrying in the addition process.
▪
Solve addition problems with denominate numbers.
The four basic operations of arithmetic are addition, subtraction, multiplication,
and division. Addition will be discussed in this unit.
Addition
is the process of
combining two or more numbers to obtain a combined quantity called the sum. A
plus sign (+)
is used to indicate the numbers being added.
Method Used to Add Whole Numbers
+ =
Viktor Chursin/Shutterstock.com
When adding denominate numbers, the unit of measure is applied to the answer as
well. Shown below, the sum of adding four bags of concrete and another two bags adds
up to six bags of concrete. Numbers can be added either horizontally or vertically.
Horizontal addition:
4 + 2 = 6
Vertical addition:
4
+ 2
‾
6
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Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website.
1
Whole
Numbers
SECTION
1
Unit 1. Basic Principles of Whole Numbers
Unit 2.
Adding Whole Numbers
Unit 3. Subtracting Whole Numbers
Unit 4.
Multiplying Whole Numbers
Unit 5.
Dividing Whole Numbers
Key Terms
addition
borrowing
carrying
decimal number system
denominate number
difference
digits
dividend
division
division sign (÷)
divisor
equals sign (=)
minus sign (–)
multiplication
multiplication sign (×)
place value
plus sign (+)
product
quotient
remainder
rounding
subtraction
sum
whole number
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Unit 15 Linear Measurement 175
Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website.
Each inch within the scale is then broken up into fractional parts of an inch, or
graduations,equalthe so scale can be used to make precise measurements. Cutting the
inch in two parts creates a 1/2″
line, and cutting the two halves equally creates
1/4″ lines. Cutting the quarters equally creates 1/8
″ lines, and fi
nally cutting the
eighths in half creates 1/16″
lines. Some measuring instruments are graduated down
further to 1/64″, but measuring in the construction trades generally is taken to 1/16″.
To help identify the value of the graduations on a rule, the lines vary in length.
The whole inch marks are the longest with lines reducing in length down to 1/16″.
0 1
1
16
3
16
1
8
1
4
3
4 1
2
3
8
5
8
7
8
5
16
7
16
9
16
11
16
13
16
15
16
Goodheart-Willcox Publisher
Math Tip
All fractional inch measurements will be reduced to the lowest terms. The 1/16″
lines with even numbered numerators will always reduce to an eighth, quarter, or half. For
example, 4/16″ = 1/4″.
When an object is measured with the scale, its length is determined by sequentially
reading the graduations fi
rst in whole inches, determining the fractional value, and
then combining the two.
Example 15-1
What is the value indicated below?
1
9 10
11F
12 13
1
14
2
15
3
10″
Whole
inches
1/2″
Fractional
inches
Goodheart-Willcox Publisher
Combine the whole and fractional inches to determine the value.
10″ + 1/2″ = 10 1/2″
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vi
Features of the Textbook
Features are student-focused learning tools designed
to help you get the most out of your studies. This visual
guide highlights the features designed for the textbook.
Section Outlines list the units
in each section.
Math Tips underscore important points and
provide additional easy-to-understand examples.
Objectives clearly identify
the knowledge and skills
to be obtained when the
unit is completed.
Examples demonstrate the
concept that has just been
presented, showing all the
work needed to solve a
mathematical problem.
Key Terms list the
important terms to be
learned in the section.