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Lesson Presentation. Lesson Quizzes. Sunshine State Standards. Preview of MA.7.A.3.1 Use and justify the rules for…subtracting…integers. Preview of MA.7.A.3.2 Subtract…integers,…including solving problems in everyday contexts. Subtracting Integers on a Number Line.
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Lesson Presentation Lesson Quizzes
Sunshine State Standards Preview of MA.7.A.3.1 Use and justify the rules for…subtracting…integers. Preview of MA.7.A.3.2 Subtract…integers,…including solving problems in everyday contexts.
Subtracting Integers on a Number Line Move left on a number line to subtract a positive integer. Move right on a number line to subtract a negative integer. Confused???
Slash & Dash • When subtracting a positive number – use “SLASH & DASH” • -4 – 3 = • Keep the -4 • SLASH the subtraction symbol (+) • Mark a DASH on the 3 to make it negative • -4 + -3 = -7
Slash & Slash • When subtracting a negative number – use “SLASH & SLASH” • -4 – -3 = • Keep the -4 • SLASH the subtraction symbol (+) • SLASH the -3 to make it a positive 3 • -4 + +3 = -1
Keep, Change, Change • Some teachers teach Slash/Slash or Slash/Dash as • KEEP, CHANGE, CHANGE
Additional Example 1: Writing Integer Subtraction Write the subtraction modeled on each number line. A. B. –3 –4 –8 –7 – 6 –5 –4 –3 –2 –1 0 1 The subtraction modeled is –3 – 4 = –7. – (–9) (–5) –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 The subtraction modeled is –5 – (–9) = 4.
Check It Out: Example 1 Write the subtraction modeled on each number line. A. B. –5 –2 –8 –7 – 6 –5 –4 –3 –2 –1 0 1 The subtraction modeled is –5 – 2 = –7. –(–5) (–3) –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 The subtraction modeled is –3 – (–5) = 2.
Additional Example 2A: Subtracting Integers Find the difference. 4 – 6 (–6) 4 –3 –2 –1 0 1 2 3 4 5 4 – 6 = –2
–1 0 1 2 3 4 5 6 7 Additional Example 2B: Subtracting Integers Find the difference. 3 – (–3) 3 –(–3) 3 – (–3) = 6
Check It Out: Example 2A Find the difference. 2 – (–5) – (–5) 2 –1 0 1 2 3 4 5 6 7 2 – (–5) = 7
Check It Out: Example 2B Find the difference. 3 – 6 (–6) 3 –3 –2 –1 0 1 2 3 4 5 3 – 6 = –3
Additional Example 3: Evaluating Integer Expressions Evaluate a – 4 for a = 2. a – 4 Write the expression. 2 – 4 Substitute 2 for a. –2 Subtract.
Check It Out: Example 3 Evaluate b – 6 for b= 8. b – 6 Write the expression. 8 – 6 Substitute 8 for b. 2 Subtract.
Lesson Quiz Standard Lesson Quiz
Lesson Quiz Find each difference. 1. 8 – 5 2. –9 – (–3) Evaluate x – (–7) for each value of x. 3.x = –2 4.x = 5 5. The peak of Mt. Everest is approximately 26,544 ft above sea level. The shore of the Dead Sea is about 1,200 ft below sea level. How much higher is the peak of Mt. Everest than the shore of the Dead Sea? –6 3 12 5 27,744 ft
Lesson Quiz 1. Find the difference. 9 – 6 A. 3 B. –3 C. 15 D. –15
Lesson Quiz 2. Find the difference. –11 – (–8) A. 3 B. –3 C. 19 D. –19
Lesson Quiz 3. Evaluate p – (–8) for p = –9. A. 17 B. 1 C. –1 D. –17
Lesson Quiz 4. Evaluate s – (–8) for s = 13. A. 21 B. 5 C. –5 D. –21
Lesson Quiz 5. A submarine is 150 feet below the sea level. An airplane is 1,000 feet above the sea level and directly above the submarine. What is the distance between the airplane and the submarine? A. 850 ft B. 1,000 ft C. 1,150 ft D. 1,500 ft