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

Warm Up Graph each number on a number line. 1. – –44. 0 Course Adding Integers –5 –4 –3 –2 –

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? Course Adding Integers (–2, –2)

Learn to add integers. Course Adding Integers

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

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

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

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

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

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

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

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

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

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

Course 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 (–166) + (–38) Group integers with same signs. ( ) + (–166 + –38) Add integers within each group (–204) 220 > 204; use the sign of Meka’s account balance after the first four transactions is $16.

Course 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 (–133) + (–65) Group integers with same signs. ( ) + (–133 + –65) Add integers within each group (–198) 270 > 198; use the sign of Michael’s account balance after the first four transactions is $72.

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

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? Insert Lesson Title Here Course Adding Integers 5 dogs