2-2 Adding Integers Warm Up Problem of the Day Lesson Presentation Course 2 Warm Up Problem of the Day Lesson Presentation

2-2 Adding Integers Warm Up Find each absolute value. 1. |8| 2. |–6| Course 2 2-2 Adding Integers Warm Up Find each absolute value. 1. |8| 2. |–6| 3. |–9| 4. |–7| 5. |–12| 6. |53| 8 6 9 7 12 53

2-2 Adding Integers Problem of the Day Course 2 2-2 Adding Integers Problem of the Day Jan’s yearly salary is $30,000, and it will be increased by $3,000 each year. Phil’s salary is $20,000, and it will be increased by $5,000 each year. In how many years will Jan and Phil both have the same yearly salary? 5 years

Course 2 2-2 Adding Integers Learn to add integers.

Additional Example 1A: Modeling Integer Addition Course 2 2-2 Adding Integers Additional Example 1A: Modeling Integer Addition Use a number line to find each sum. –7 + (–4) +(–4) –7 2 –14 –12 –10 –8 –6 –4 –2 0 Start at 0. Move left 7 spaces. Then move left 4 more spaces. –7 + (–4) = –11

Additional Example 1B: Modeling Integer Addition Course 2 2-2 Adding Integers Additional Example 1B: Modeling Integer Addition Use a number line to find each sum. –12 + 19 19 –12 2 4 6 8 –12 –10 –8 –6 –4 –2 0 Start at 0. Move left 12 spaces. Then move right 19 spaces. –12 + 19 = 7

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Check It Out: Example 1A Use a number line to find each sum. –4 + (–5) +(–5) –4 2 –14 –12 –10 –8 –6 –4 –2 0 Start at 0. Move left 4 spaces. Then move left 5 more spaces. –4 + (–5) = –9

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Check It Out: Example 1B Use a number line to find each sum. –7 + 12 12 –7 2 4 6 8 –12 –10 –8 –6 –4 –2 0 Start at 0. Move left 7 spaces. Then move right 12 spaces. –7 + 12 = 5

Adding Integers 2-2 Adding Integers Course 2 2-2 Adding Integers Adding Integers To add two integers with the same sign, find the sum of their absolute values. Use the sign of the two integers. To add two integers with different signs, find the difference of their absolute values. Use the sign of the integer with the greater absolute value.

Additional Example 2A: Adding Integers Using Absolute Values Course 2 2-2 Adding Integers Additional Example 2A: Adding Integers Using Absolute Values Find each sum. –4 + 8 The signs are different. Find the difference of the absolute values. –4 + 8 Think: 8 – 4 = 4. Use the sign of the integer with the greater absolute value. 4

Additional Example 2B: Adding Integers Using Absolute Values Course 2 2-2 Adding Integers Additional Example 2B: Adding Integers Using Absolute Values Find each sum. 23 + (–35) The signs are different. Find the difference of the absolute values. 23 + (–35) Think: 35 – 23 = 12. Use the sign of the integer with the greater absolute value. –12

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Check It Out: Example 2A Find each sum. –5 + 3 The signs are different. Find the difference of the absolute values. –5 + 3 Think: 5 – 3 = 2. Use the sign of the integer with the greater absolute value. –2

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Check It Out: Example 2B Find each sum. –13 + (–24) The signs are the same. Find the sum of the absolute values. –13 + (–24) Think: 13 + 24 = 37. –37 Use the sign of the two integers.

Additional Example 3: Evaluating Expressions with Integers Course 2 2-2 Adding Integers Additional Example 3: Evaluating Expressions with Integers Evaluate x + y for x = –42, y = 71. x + y Substitute for x and y. –42 + 71 The signs are different. Think 71- 42 = 29 Use the sign of the integer with the greater absolute value (positive). 29 When adding integers, think: if the signs are the same, find the sum. If the signs are different, find the difference. Helpful Hint

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Check It Out: Example 3 Evaluate x + y for x = –24, y = 17. x + y Substitute for x and y. –24 + 17 The signs are different. Think: 24 – 17 = 7. –7 Use the sign of the integer with the greater absolute value (negative).

Additional Example 4: Application Course 2 2-2 Adding Integers Additional Example 4: Application 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. 286 + (–21) Use negative for the expenses. Find the differences of the absolute values. 286 – 21 265 The answer is positive. The band earned $265.

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here 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. 730 + (–52) Use negative for the expenses. Find the differences of the absolute values. 730 – 52 678 The answer is positive. The club earned $678.

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Lesson Quiz: Part I Use a number line to find the sum. 1. –7 + (–6) Find each sum. 2. –15 + 24 + (–9) 3. –24 + 7 + (–3) 4. Evaluate x + y for x = –2 and y = –15. –13 2 –14 –12 –10 –8 –6 –4 –2 0 –20 –17

Insert Lesson Title Here Course 2 2-2 Adding Integers Insert Lesson Title Here Lesson Quiz: Part II 5. The math club’s income from a bake sale was $217. Advertising expenses were $32. Use integer addition to find the club’s total profit or loss? $185 profit