1-4 Adding Integers Warm Up Problem of the Day Lesson Presentation Course 3 Warm Up Problem of the Day Lesson Presentation

1-4 Adding Integers Warm Up Graph each number on a number line. Course 3 1-4 Adding Integers Warm Up Graph each number on a number line. 1. –5 2. 7 3. –4 4. 0 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7

1-4 Adding Integers Problem of the Day Course 3 1-4 Adding Integers Problem of the Day Start at (0, 0). Walk 3 blocks west and 2 blocks north. Then walk 4 blocks south and 1 block east. What are your coordinates? (–2, –2)

Course 3 1-4 Adding Integers Learn to add integers.

Additional Example 1A: Using a Number Line to Add Integers Course 3 1-4 Adding Integers Additional Example 1A: Using a Number Line to Add Integers Use a number line to find the sum. (–6) + 2 –6 2 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 You finish at –4, so (–6) + 2 = –4. To add a positive number move to the right. To add a negative number move to the left. Helpful Hint

Additional Example 1B: Using a Number Line to Add Integers Course 3 1-4 Adding Integers Additional Example 1B: Using a Number Line to Add Integers Use a number line to find the sum. –3 + (–6) –6 -3 –9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2 You finish at –9, so –3 + (–6) = –9.

1-4 Adding Integers –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 Course 3 1-4 Adding Integers Check It Out: Example 1A Use a number line to find the sum. (–3) + 7 –3 7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 You finish at 4, so (–3) + 7 = 4.

1-4 Adding Integers –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 Course 3 1-4 Adding Integers Check It Out: Example 1B Use a number line to find the sum. (–2) + 4 –2 4 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 You finish at 2, so (–2) + 4 = 2.

Additional Example 2: Using Absolute Value to Add Integers Course 3 2-1 Adding Integers Additional Example 2: Using Absolute Value to Add Integers Add. A. 1 + (–2) 1 + (–2) Think: Find the difference of 1 and –2 . –1 2 > 1; use the sign of 2. B. (–8) + 5 (–8) + 5 Think: Find the difference of –8 and 5 . –3 8 > 5; use the sign of 8.

Additional Example 2: Using Absolute Value to Add Integers Course 3 1-4 Adding Integers Additional Example 2: Using Absolute Value to Add Integers Add. C. (–2) + (–4) (–2) + (–4) Think: Find the sum of –2 and –4 . Same sign; use the sign of the integers. –6

1-4 Adding Integers Check It Out: Example 2 Add. A. 3 + (–6) 3 + (–6) Course 3 1-4 Adding Integers Check It Out: Example 2 Add. A. 3 + (–6) 3 + (–6) Think: Find the difference of 3 and –6 . –3 6 > 3; use the sign of 6. B. (–4) + 1 (–4) + 1 Think: Find the difference of –4 and 1 . –3 4 > 1; use the sign of 4.

1-4 Adding Integers Check It Out: Example 2C Add. C. (–6) + (–7) Course 3 1-4 Adding Integers Check It Out: Example 2C Add. C. (–6) + (–7) (–6) + (–7) Think: Find the sum of –6 and –7 . Same sign; use the sign of the integers. –13

Additional Example 3: Evaluating Expressions with Integers Course 3 1-4 Adding Integers Additional Example 3: Evaluating Expressions with Integers Evaluate c + 4 for c = –8. c + 4 (–8) + 4 Replace c with –8. Think: Find the difference of –8 and 4 . –8 + 4 = –4 8 > 4; use the sign of 8.

1-4 Adding Integers Check It Out: Example 3 Evaluate d + 7 for d = –3. Course 3 1-4 Adding Integers Check It Out: Example 3 Evaluate d + 7 for d = –3. d + 7 (–3) + 7 Replace d with –3. Think: Find the difference of –3 and 7 . –3 + 7 = 4 7 > 3; use the sign of 7.

Additional Example 4: Application Course 3 1-4 Adding Integers Additional Example 4: Application Meka opened a new bank account. Find her account balance after the first four transactions listed below. Deposits: $200, $20 Withdrawals: $166, $38 Use a positive sign for deposits and a negative sign for withdrawals. 200 + 20 + (–166) + (–38) Group integers with same signs. (200 + 20) + (–166 + –38) Add integers within each group. 220 + (–204) 220 > 204; use the sign of 220. 16 Meka’s account balance after the first four transactions is $16.

1-4 Adding Integers Check It Out: Example 4 175 + 95 + (–133) + (–65) Course 3 1-4 Adding Integers Check It Out: Example 4 Michael opened a new bank account. Find his account balance after the first four transactions listed below. Deposits: $175, $95 Withdrawals: $133, $65 Use a positive sign for deposits and a negative sign for withdrawals. 175 + 95 + (–133) + (–65) Group integers with same signs. (175 + 95) + (–133 + –65) Add integers within each group. 270 + (–198) 270 > 198; use the sign of 270. 72 Michael’s account balance after the first four transactions is $72.

Insert Lesson Title Here Course 3 1-4 Adding Integers Insert Lesson Title Here Lesson Quiz: Part I Add. 1. –7 + (– 7) 2. 15 + (–9) + (–2) –14 4 Evaluate each expression for the given value of the variable. 3. 13 + r for r = –15 4. 2 + b + (–9) for b = –6 –2 –13

Insert Lesson Title Here Course 3 1-4 Adding Integers Insert Lesson Title Here Lesson Quiz: Part II 5. On Monday, a local dog shelter had six dogs. By Friday they had found homes for three, but took in two more. Then how many dogs were in the shelter? 5 dogs