a d d i n g i n t e g e r s

Warm UpFind each absolute value.

1. |8|

2. |–6|

3. |–9|

4. |–7|

5. |–12|

6. |53|

8

69

Course 2

2-2 Adding Integers

7

12

53

DRAW THIS IN YOUR SPIRAL BOUND NOTEBOOK,LANDSCAPE, AND USE ENTIRE PAGE.

EXAMPLE 1:

EXAMPLE 2:

EXAMPLE 3:

EXAMPLE 4:

NOTES:

EXAMPLE 1:

EXAMPLE 2:

EXAMPLE 3:

EXAMPLE 4:

NOTES:

Use a number line to find each sum.

EXAMPLE 1:

Course 2

2-2 Adding Integers

2 –14 –12 –10 –8 –6 –4 –2 0

–7 + (–4)–7+(–4)

–7 + (–4) = –11

Start at 0. Move left 7 spaces.

Then move left 4 more spaces.

EXAMPLE 1:

EXAMPLE 2:

EXAMPLE 3:

EXAMPLE 4:

NOTES:

Use a number line to find each sum.

EXAMPLE 2:

Course 2

2-2 Adding Integers

–12 + 19

–12

19

–12 + 19 = 7

Start at 0.

2 4 6 8

–12 –10 –8 –6 –4 –2 0

Move left 12 spaces.

Then move right 19 spaces.

EXAMPLE 1:

EXAMPLE 2:

EXAMPLE 3:

EXAMPLE 4:

NOTES:

EXAMPLE 3:

Insert Lesson Title Here

Course 2

2-2 Adding Integers

Use a number line to find each sum.

2 –14 –12 –10 –8 –6 –4 –2 0

–4 + (–5)–4+(–5)

–4 + (–5) = –9

Start at 0. Move left 4 spaces. Then move left 5 more spaces.

EXAMPLE 1:

EXAMPLE 2:

EXAMPLE 3:

EXAMPLE 4:

NOTES:

EXAMPLE 4 :

Insert Lesson Title Here

Course 2

2-2 Adding Integers

Use a number line to find each sum.

–7 + 12

–7

12

–7 + 12 = 5

Start at 0.

2 4 6 8

–12 –10 –8 –6 –4 –2 0

Move left 7 spaces.

Then move right 12 spaces.

1.) 7 + (-2 ) = 2.) 6 +(-8) =

3.) -6 + -14 = 4.) -6 + (-8) =

5.) -7 + 5 = 6.) -8 + -13 =

7.) 5 + 6 = 8.) - 9 + 10 =

DRAW A NUMBER LINE FOR EACH PROBLEM:

RULES FOR ADDING SIGNED NUMBERS

DIRECTIONS FOR FOLDABLE:

1st – fold on

dashed line

2nd – cut on

dotted line

Outside View of Flaps

When adding positive

numbers.

When adding

negative numbers.

When adding a

positive anda negative number.

1.) Add the absolute values.

2.) Answer is positive.

1.) Add the absolute values.

2.) Answer is negative.

1.) Subtract the absolute values.2.) Answer takes the sign of the number with the greatest absolute value.EXAMPLES: EXAMPLES: EXAMPLES:

Find each sum.

EXAMPLE #1 UNDER FLAP 1

Course 2

2-2 Adding Integers

15 + 25* What are we adding?

15 =

***What is the sign of the answer?

40

Positive numbers.

** Add the absolute values.

15 + 25 =

(positive)

and 25 =

40

=

15 25

Find each sum.

EXAMPLE #1 UNDER FLAP 2

Course 2

2-2 Adding Integers

–13 + (–24)* What are we adding?

–13 =

***What is the sign of the answer?

-37

Negative numbers.

** Add the absolute values.

13 + 24 =

(negative)

and –24 =

37

=

13 24

Find each sum.

EXAMPLE #1 UNDER FLAP 3

Course 2

2-2 Adding Integers

–4 + 8* What are we adding?

- 4 =

***What is the sign of the answer?

4

A negative and a positive.

** Subtract the absolute values.

8 – 4 =

(positive)

and 8 =

4

=

4 8

Find each sum.

EXAMPLE #2 UNDER FLAP 1

Course 2

2-2 Adding Integers

43 + 61* What are we adding?

43 =

***What is the sign of the answer?

104

Positive numbers.

** Add the absolute values.

43 + 61 =

(positive)

and 61 =

104

=

43 61

Find each sum.

EXAMPLE #2 UNDER FLAP 2

Course 2

2-2 Adding Integers

–5 + – 3* What are we adding?

–5 =

***What is the sign of the answer?

-8

Negative numbers.

** Add the absolute values.

5 + 3 =

(negative)

and – 3 =

8

=

5 3

Find each sum.

EXAMPLE #2 UNDER FLAP 3

Course 2

2-2 Adding Integers

23 + (–35)* What are we adding?

23 =

***What is the sign of the answer?

-12

A negative and a positive.

** Subtract the absolute values.

35 – 23 =

(negative)

and –35 =

12

=

23 35

2.) 165 + (– 321) =

3.) – 68 + – 107 = 4.) – 34 + – 523 + 71 =

1.) – 41 + 643 + 86 =

ON YOUR OWN – INDEPENDENT PRACTICE

Evaluate x + y for x = –42, y = 71.

ON BACK OF FOLDABLE:

Course 2

2-2 Adding Integers

x + y–42

Substitute x and y with the given values.

* What are we adding? *A negative and a Positive.

** Subtract the absolute values.

-42 = and 71 =

71 - 42 =

***What is the sign of the answer?

(positive) 29

+ 71

29

42 71

=

EVALUATING ALGEBRAIC EXPRESSIONS:

Evaluate x + y for x = –24, y = –17.

ON BACK OF FOLDABLE:

Course 2

2-2 Adding Integers

x + y–24

Substitute x and y with the given values.

* What are we adding? *Negative numbers.

** Add the absolute values.

-24 = and –17 =

24 + 17 =

***What is the sign of the answer?

(negative) – 41

+ – 17

41

24 17

=

EVALUATING ALGEBRAIC EXPRESSIONS:

2.) c + (- 8) =

3.) a + b = 4.) c + 5 + a =

1.) 14 + b =

INDEPENDENT PRACTICEEvaluate each expression for a = - 15, b = - 8, and c = 6.

The jazz band’s income from a bake sale was $286. Expenses were $21. Use integer addition to find the band’s total profit or loss.

Additional Example 4: Application

Course 2

2-2 Adding Integers

286 + (–21)

286 – 21

265

The band earned $265.

Use negative for the expenses.

Subtract the absolute values.

The answer is positive.

Check it Out: Example 4

The French Club was raising money for a trip to Washington D.C. Their car wash raised $730. They had expenses of $52. Use integer addition to find the club’s total profit or loss.

Insert Lesson Title Here

Course 2

2-2 Adding Integers

730 + (–52)

730 – 52

678

The club earned $678.

Use negative for the expenses.

Subtract the absolute values.

The answer is positive.

Adding Integers Problem Solving 2-2

The temperature dropped 12°F in 8 hours. If the final temperature was- 7°F, what was the starting temperature?

Adding Integers Problem Solving 2-2

At 4 P.M., the temperature was 9°F. By 11 P.M., it had dropped 31°F. What was the temperature as 11 P.M.?

Adding Integers Problem Solving 2-2

Tad owes John $23 and borrows $12 more. How much does Tad owe John now?

Adding Integers Problem Solving 2-2

New Orleans, Louisiana, is 6 feet below sea level. The highest point in Louisiana. Driskill Mountain, is 541 feet higher than New Orleans. How high is Driskill Mountain?

Adding Integers Problem Solving 2-2

A submarine submerged at a depth of – 40 ft. dives 57 ft. more. What is the new depth of the submarine?

Adding Integers Problem Solving 2-2

An airplane at 20,000 ft. drops 2,500 ft. in altitude. What is the new altitude?

Adding Integers Problem Solving 2-2

Last week, Jane made deposits of $64, $25, and $37 into her checking account. She then wrote checks for $52 and $49. What is the overall change in Jane’s account balance?

A. - $99

B. $25

C. $126

D. $227

Adding Integers Problem Solving 2-2

In Indianapolis, Indiana, the coldest recorded temperature was - 23°F. The hottest recorded temperature was 127°F higher. What was the hottest temperature in Indianapolis?

A. 150°F

B. 127°F

C. 104°F

D. -150°F

Adding Integers Problem Solving 2-2

Helena borrowed $189 from her parents to buy an electric bass. She paid back $56 last week and $64 this week. How much does Helena still owe her parents?

A. $133

B. $120

C. $69

D. $29

Adding Integers Problem Solving 2-2

The Aral Sea and the Caspian Sea are actually lakes. The elevation of the Caspian Sea is 92 feet below sea level. The Aral Sea is 217 feet higher. What is the elevation of the Aral Sea?

A. – 125 ft

B. – 309 ft

C. 309 ft

D. 125 ft