Add. See Examples 1 through 7.EXAMPLE 1Add: 3 + 2Solution Recall that 3 and 2 are called a...

Add. See Examples 1 through 7.

EXAMPLE 1

Add: 3 + 2

Solution Recall that 3 and 2 are called addends. We start at 0 on a number line and draw an arrow representing the addend 3. This arrow is three units long and points to the right since 3 is positive. From the tip of this arrow, we draw another arrow, representing the addend 2. The number below the tip of this arrow is the sum, 5.

EXAMPLE 2

Add: − 1 + (− 2)

Solution Here, − 1 and − 2 are addends. We start at 0 on a number line and draw an arrow representing − 1. This arrow is one unit long and points to the left since − 1 is negative. From the tip of this arrow, we draw another arrow, representing − 2. The number below the tip of this arrow is the sum, − 3.

EXAMPLE 3

Add.

a. − 3 + (− 7)

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b. − 1 + (− 20)

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c. − 2 + (− 10)

Solution Notice that each time, we are adding numbers with the same sign.

a.

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b.

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c.

EXAMPLE 4

Add: − 4 + 6

Solution

EXAMPLE 5

Add.

a. 3 + (− 7)

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b. − 2 + 10

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c. 0.2 + (− 0.5)

Solution Notice that each time, we are adding numbers with different signs.

a.

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b.

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c.

EXAMPLE 6

Add.

a. − 8 + (− 11)

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b. − 5 + 35

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c. 0.6 + (− 1.1)

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d.

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e. 11.4 + (− 4.7)

f.

Solution

EXAMPLE 7

Add.

a. 3 + (− 7) + (− 8)

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b. [7 + (− 10)] + [− 2 + |− 4|]

Solution

a. Perform the additions from left to right.

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b. Simplify inside brackets first.

8 + (− 7)