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Subtract + and – fractions and decimals. Warm-Up. Find the value of each expression. −3 +(− 4) 10 − (−5) −25 − 10 − 8.3 + 45.2. RULES. 5. 2 + 3. Change subtract into add add the opposite – 2.2 – 4.2 – 2.2 – (4.2) – 2.2 + ( – 4.2) Follow the rules for adding
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Warm-Up Find the value of each expression. • −3 +(− 4) • 10 − (−5) • −25 − 10 • − 8.3 + 45.2
RULES 5 2 + 3 • Change subtract into add add the opposite – 2.2 – 4.2 – 2.2 – (4.2) – 2.2 + (– 4.2) • Follow the rules for adding neg + neg = ADD answer is negative neg + pos = Subtract pos + neg = Subtract 1 3 – 2
Example 1 Find the value of . • Add the opposite. • Make improper fractions. • Rewrite with common denominators. • Add and simplify.
Example 2 Bromine has a boiling point of 58.8⁰ C and a melting point of –7.2⁰ C. What is the difference between the boiling point and the melting point? • Write the problem: 58.8 – (–7.2) • Add the opposite: 58.8 + 7.2 • Add by lining up the decimals.
Exit Problems Find each difference. • 18.7 − (−2.8)
Communication Prompt Science and math are related in many ways. What is one way you have observed that math and science overlap?