1. Holt CA Course 1 2-3 Subtracting Integers NS2.3 Solve addition, subtraction, multiplication, and division problems, including those arising in concrete situations, that use positive and negative integers and combinations of these operations. Also covered: AF1.2 California Standards

2. Holt CA Course 1 2-3 Subtracting Integers VOCABULARY CARDS Subtracting Integers with the Same Sign Subtracting Integers with Different Signs

3. Holt CA Course 1 2-3 Subtracting Integers You can subtract an integer by adding its opposite. You can then use the rules for addition of integers.

4. Holt CA Course 1 2-3 Subtracting Integers Find each difference. Example 1: Subtracting Integers by Adding the Opposite 1A. 5 – (–2) 5 + 2 7 1B. –3 – 7 –3 + (–7) –10 1C. – 1 – (–8) –1 + 8 7 Add the opposite of –2. Add the opposite of 7. Add the opposite of –8.

5. Holt CA Course 1 2-3 Subtracting Integers Practice 1: Find each difference. 1A. 4 – 2 4 + (–2) 2 1B. –2 – (–6) –2 + 6 4 1C. –1 – 4 –1 + (–4) –5 Add the opposite of 2. Add the opposite of –6. Add the opposite of 4.

6. Holt CA Course 1 2-3 Subtracting Integers Evaluate x – y for each set of values. Example 2: Evaluating Expressions with Integers 2A. x = –3 and y = 2 x – y –3 – 2 = –3 + (–2) = –5 2B. x = 4 and y = –6 x – y 4 – (–6) = 4 + 6 = 10 Substitute for x and y. Add the opposite of 2. Substitute for x and y. Add the opposite –6.

7. Holt CA Course 1 2-3 Subtracting Integers Practice 2: Evaluate x – y for each set of values. 2A. x = –4 and y = –3 x – y –4 – (–3) = –4 + 3 = –1 2B. x = –4 and y = 5 x – y –4 – 5 = –4 + (–5) = –9 Substitute for x and y. Add the opposite of –3. Substitute for x and y. Add the opposite of 5.

8. Holt CA Course 1 2-3 Subtracting Integers Find the difference between 32°F and –10°F. Example 3: Temperature Application 32 – (–10) 32 + 10 = 42 The difference in temperature is 42°F. Add the opposite of –10.

9. Holt CA Course 1 2-3 Subtracting Integers Practice 3: Find the difference between 8°F and –5°F. 8 – (–5) 8 + 5 = 13 The difference in temperature is 13°F. Add the opposite of 5.

10. Holt CA Course 1 2-3 Subtracting Integers Lesson Quiz Use a number line to find the difference. 1. 3 – 9 Find each difference. 2. –7 – 43. –3 – (–5) 4. Evaluate x – y + z for x = –4, y = 5, and z = –10. –11 –6 2 –19 5. On January 1, 2002, the high temperature was 81F in Kona, Hawaii. The low temperature was –29F in Barrow, Alaska. What was the difference between the two temperatures? 110F