Multiply and Divide Intergers (1).ppt
- 2. Warm Up Evaluate each expression. 1. 17 · 5 2. 8 · 34 3. 4 · 86 4. 20 · 850 5. 275 ÷ 5 6. 112 ÷ 4 85 272 344 Course 2 Multiplying and Dividing Integers 17,000 55 28
- 3. Learn to multiply and divide integers. Multiplying and Dividing Integers
- 4. Multiplying and Dividing Integers You can think of multiplication as repeated addition. 3 · 2 = 2 + 2 + 2 = 6 and 3 · (–2) = (–2) + (–2) + (–2) = –6
- 5. Find each product. Additional Example 1: Multiplying Integers Using Repeated Addition Multiplying and Dividing Integers A. –7 · 2 –7 · 2 = (–7) + (–7) = –14 B. –8 · 3 –8 · 3 = (–8) + (–8) + (–8) = –24 Think: –7 · 2 = 2 · –7, or 2 groups of –7. Think: –8 · 3 = 3 · –8, or 3 groups of –8.
- 6. Try This: Example 1 Insert Lesson Title Here Multiplying and Dividing Integers Find each product. A. –3 · 2 –3 · 2 = (–3) + (–3) = –6 B. –5 · 3 –5 · 3 = (–5) + (–5) + (–5) = –15 Think: –3 · 2 = 2 · –3, or 2 groups of –3. Think: –5 · 3 = 3 · –5, or 3 groups of –5.
- 7. Course 2 Multiplying and Dividing Integers The Commutative Property of Multiplication states that order does not matter when you multiply. Remember!
- 8. Course 2 Multiplying and Dividing Integers Example 1 suggests that when the signs of two numbers are different, the product is negative. To decide what happens when both numbers are negative, look at the pattern at right. Notice that each product is 3 more than the preceding one. This pattern suggests that the product of two negative integers is positive. –3 · (2) = –6 –3 · (1) = –3 –3 · (0) = 0 –3 · (–1) = 3 –3 · (–2) = 6
- 9. Multiply. Additional Example 2: Multiplying Integers Course 2 Multiplying and Dividing Integers –6 · (–5) –6 · (–5) = 30 Both signs are negative, so the product is positive.
- 10. Try This: Example 2 Insert Lesson Title Here Course 2 Multiplying and Dividing Integers Multiply. –2 · (–8) –2 · (–8) = 16 Both signs are negative, so the product is positive.
- 11. Course 2 Multiplying and Dividing Integers Multiplication and division are inverse operations. They “undo” each other. You can use this fact to discover the rules for division of integers.
- 12. Course 2 Multiplying and Dividing Integers Same signs Positive Different signs Negative The rule for division is like the rule for multiplication. 4 • (–2) = –8 –4 • (–2) = 8 –8 ÷ (–2) = 4 8 ÷ (–2) = –4
- 13. Course 2 Multiplying and Dividing Integers MULTIPLYING AND DIVIDING INTEGERS MULTIPLYING AND DIVIDING INTEGERS If the signs are: Your answer will be: the same different positive negative
- 14. Find each quotient. Additional Example 3A & 3B: Dividing Integers Course 2 Multiplying and Dividing Integers A. –27 ÷ 9 –27 ÷ 9 –3 B. 35 ÷ (–5) 35 ÷ (–5) –7 Think: 27 ÷ 9 = 3. The signs are different, so the quotient is negative. Think: 35 ÷ 5 = 7. The signs are different, so the quotient is negative.
- 15. Additional Example 3C: Dividing Integers Course 2 Multiplying and Dividing Integers Find the quotient. C. –32 ÷ (–8) –32 ÷ –8 4 Think: 32 ÷ 8 = 4. The signs are the same, so the quotient is positive.
- 16. Try This: Example 1A & 1B Insert Lesson Title Here Course 2 Multiplying and Dividing Integers Find each quotient. A. –12 ÷ 3 –12 ÷ 3 –4 B. 45 ÷ (–9) 45 ÷ (–9) –5 Think: 12 ÷ 3 = 4. The signs are different, so the quotient is negative. Think: 45 ÷ 9 = 5. The signs are different, so the quotient is negative.
- 17. Try This: Example 3C Insert Lesson Title Here Course 2 Multiplying and Dividing Integers Find the quotient. C. –25 ÷ (–5) –25 ÷ –5 5 Think: 25 ÷ 5 = 5. The signs are the same, so the quotient is positive.
- 18. Lesson Quiz Find each product or quotient. 1. –8 · 12 2. –3 · 5 · (–2) 3. –75 ÷ 5 4. –110 ÷ (–2) 5. The temperature at Bar Harbor, Maine, was –3°F. It then dropped during the night to be 4 times as cold. What was the temperature then? –96 Insert Lesson Title Here –15 55 Course 2 Multiplying and Dividing Integers 30 –12˚F
- 19. 6. Lito wants to hand sanitizers for his family. If there are 6 members in the family and each sanitizer costs Php 55, how much does he need to pay for the sanitizers. 7.During pandemic crisis , Ruth borrowed Php 12,000 from her sister to sustain their basic needs. She promised to promised to pay for 6 months. How much does she need to pay for each month? 8. Aileen invited her 3 friends for a visit to an intimate birthday celebration. They rode a tricycle that charged Php 18 per passenger. How much did she pay for their fare expenses.
- 20. 9. There are 280 stranded passengers because of lockdown. If a bus can only accommodate 20 passengers, how many buses they need?