11-8 Dividing Integers Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes

11-8 Dividing Integers Warm Up Find each quotient ÷ ÷ ÷ ÷ ,600 ÷ ÷

11-8 Dividing Integers Problem of the Day Hank wanted to record the number of marbles he lost to his friend Marcus each day for 5 days. He forgot to record one day, but for the other days he wrote 8, 2, 3, and 4. The average number he lost was 4. What number did he forget to write? 3

11-8 Dividing Integers Learn to divide integers.

11-8 Dividing Integers Multiplication and division are inverse operations. To solve a division problem, think of the related multiplication. To find the mean of a list of numbers: 1. Add all the numbers together. 2. Divide by how many numbers are in the list. Remember!

11-8 Dividing Integers Additional Example 1: Dividing Integers Find each quotient. A. –30 ÷ 6 B. –42 ÷ (–7) ‏ Think: What number times 6 equals –30? –5 6 = –30, so –30 ÷ 6 = –5. Think: What number times –7 equals –42? 6 (–7) = –42, so –42 ÷ (–7) = 6.

11-8 Dividing Integers Check It Out: Example 1 Find each quotient. A. –15 ÷ 5 B. –36 ÷ (–6) ‏ Think: What number times 5 equals –15? –3 5 = –15, so –15 ÷ 5 = –3. Think: What number times –6 equals –36? 6 (–6) = –36, so –36 ÷ (–6) = 6.

11-8 Dividing Integers If the signs are the same, the product is positive. 24 ÷ 3 = 8 –6 ÷ (–3) = 2 If the signs are different, the quotient is negative. –20 ÷ 5 = –4 72 ÷ (–8) = –9 Zero divided by any integer equals 0. = 0 = __ 0 –11 __ You cannot divide any integer by 0. Because division is the inverse of multiplication, the rules for dividing integers are the same as the rules for multiplying integers.

11-8 Dividing Integers Additional Example 2A: Evaluating Integer Expressions Evaluate for each value of d. d = 16 Write the expression. = 16 ÷ 4 Substitute 16 for d. = 4 The signs are the same, so the answer is positive. d 4 __ d __

11-8 Dividing Integers Additional Example 2B: Evaluating Integer Expressions Evaluate for each value of d. d = –24 Write the expression. = –24 ÷ 4 Substitute –24 for d. = –6 The signs are different, so the answer is negative. d 4 __ d ___

11-8 Dividing Integers Additional Example 2C: Evaluating Integer Expressions Evaluate for each value of d. d = –12 Write the expression. = –12 ÷ 4 Substitute –12 for d. = –3 The signs are different, so the answer is negative. d 4 __ d ___

11-8 Dividing Integers Check It Out: Example 2A Evaluate for each value of c. c = –15 Write the expression. = –15 ÷ 3 Substitute –15 for c. = –5 The signs are different, so the answer is negative. c 3 __ c ___

11-8 Dividing Integers Check It Out: Example 2B Evaluate for each value of c. c = 12 Write the expression. = 12 ÷ 3 Substitute 12 for c. = 4 c 3 __ c ___ The signs are the same, so the answer is positive.

11-8 Dividing Integers Check It Out: Example 2C Evaluate for each value of c. c = 27 Write the expression. = 27 ÷ 3 Substitute 27 for c. = 9 The signs are the same, so the answer is positive. c 3 __ c __

11-8 Dividing Integers Standard Lesson Quiz Lesson Quizzes Lesson Quiz for Student Response Systems

11-8 Dividing Integers Lesson Quiz Find each quotient ÷ (–3)2. –36 ÷ (–6) 3. –64 ÷ (–8)4. –45 ÷ 3 Evaluate for each value of x. 5. x = –126. x = Carmen’s mom has $3,200 in her bank account. If she uses the money to make monthly rent payments of $375, how many whole payments can she make? 6 –6 8 –15 –3 5 8 x 4 __

11-8 Dividing Integers 1. Identify the quotient. 32 ÷ (–4) A. –8 B. –28 C. –26 D. –128 Lesson Quiz for Student Response Systems

11-8 Dividing Integers 2. Identify the quotient. –55 ÷ (–5) A. 60 B. 11 C. –60 D. –11 Lesson Quiz for Student Response Systems

11-8 Dividing Integers 3. Evaluate z ÷ 5 for z = –45. A. –9 B. –40 C. –50 D. –225 Lesson Quiz for Student Response Systems

11-8 Dividing Integers 4. Stacey has 1,500 grams of flour. She needs 275 grams of flour to bake a cake. How many whole cakes can she bake? A. 3 B. 4 C. 5 D. 6 Lesson Quiz for Student Response Systems