Adding Integers Warm Up Problem of the Day

Adding Integers Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

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

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

Adding Integers Learn to add integers.

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

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

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

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

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.

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

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

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

Adding Integers Check It Out: Example 2 B 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.

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 29 The signs are different. Think 71 - 42 = 29 Use the sign of the integer with the greater absolute value (positive). Helpful Hint When adding integers, think: if the signs are the same, find the sum. If the signs are different, find the difference.

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

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) 286 – 21 265 Use negative for the expenses. Find the difference of the absolute values. The answer is positive. The band earned $265.

Adding Integers 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) 730 – 52 678 Use negative for the expenses. Find the difference of the absolute values. The answer is positive. The club earned $678.

Adding Integers Lesson Quizzes Standard Lesson Quiz for Student Response Systems

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

Adding Integers 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

Adding Integers Lesson Quiz for Student Response Systems 1. Identify the number line that helps to find the sum. – 5 + (– 4) A. – 1 B. – 9

Adding Integers Lesson Quiz for Student Response Systems 2. Identify the sum. – 18 + 26 + (– 8) A. – 36 B. 0 C. 36 D. 52

Adding Integers Lesson Quiz for Student Response Systems 3. Identify the sum. – 26 + 8 + (– 5) A. – 23 B. – 13 C. 0 D. 23

Adding Integers Lesson Quiz for Student Response Systems 4. Evaluate x + y for x = – 5 and y = – 17. A. 22 B. 12 C. – 12 D. – 22

Adding Integers Lesson Quiz for Student Response Systems 5. The cost of a guitar is $456. Helen has $178 with her. Use integer addition to identify how much more money she needs to buy the guitar. A. $296 B. $278 C. $196 D. $116