Page 21 - Math Course 1 (Book 1)

Adding Integers

Mo. 1

Lesson 3 Adding Integers

with different Signs

KEY CONCEPTS: Words: To add integers with different signs,
1. Adding two integers with the same sign. subtract their absolute values.
2. Adding two integers with different signs. The sum is:
3. Adding more than two Integers. • Positive if the positive integer’s absolute

value is greater.
• Negative if the negative integer’s absolute
value is greater.
MO. 1 - L3a

Adding two integers with Additive Inverse
the same sign. Property

Words: The sum of any number and its additive
Vocabulary A-Z inverse is zero.

Let us learn some vocabulary Symbols: x + ( -x ) = 0

Examples: 6 + ( -6 ) = 0
Opposites

Two numbers with the same absolute value but
different signs are called opposites.
Let’s Begin
-4 and 4 are OPPOSITES

Additive inverse
Add Integers on a Number Line
An integer and its opposite are also called additive
inverses.
-5 + 5 = 0 Examples
Number Additive inverse
14 + -14 = 0 Find 3 + 4.

3 4
Key Concept

0 1 2 3 4 5 6 7 8
Adding Integers
with the Same Sign Start at zero.

Words: To add integers with the same sign, add Move three units to the right.
their absolute value.
The sum is: From there, move four more units to the right.
• Positive if both integers are positive.
• Negative if both integers are negative.
Answer 3 + 4 = 7
Examples: -5 + ( -2 ) = -7 6 + 3 = 9

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