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SUBTRACT WITH DIFFERENT DENOMINATORS. PREVIOUS KNOWLEDGE. Find the Least Common Denominators of the following: ½ and 1/3 LCD = 6 5/6 and ½ LCD = 6 4/5 and 1/3 LCD = 15 ½ and ¼ LCD = 4. SUBTRACT UNLIKE FRACTIONS. SUBTRACT WITH UNLIKE DENOMINATORS.
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SUBTRACT WITH DIFFERENT DENOMINATORS CONFIDENTIAL
PREVIOUS KNOWLEDGE • Find the Least Common Denominators of the following: • ½ and 1/3 LCD = 6 • 5/6 and ½ LCD = 6 • 4/5 and 1/3 LCD = 15 • ½ and ¼ LCD = 4 CONFIDENTIAL
SUBTRACT UNLIKE FRACTIONS CONFIDENTIAL
SUBTRACT WITH UNLIKE DENOMINATORS • To find the difference of two fractions with unlike denominators, rename the fractions using the least common denominator (LCD). Then subtract and simplify. CONFIDENTIAL
Subtract Unlike Fractions • Find 2/3 – ½ LCD = 6 2/3 = 4/6 and ½ = 3/6 2/3 – ½ = 4/6 – 3/6 = 1/6. CONFIDENTIAL
Example - 2 • Find 1/10 – 1/25 • LCD = 100 1/10 = 10/100 and 1/25 = 4/100 1/10 – 1/25 = 10/100 – 4/100 = 6/100 = 3/50 CONFIDENTIAL
Your Turn • Subtract. Write in simplest form. • 5/8 – ¼ = 3/8 • ½ - 2/5 = 1/10 c. ¾ - 1/3 = 5/12 CONFIDENTIAL
BREAK CONFIDENTIAL
Evaluate an expression with fractions • Evaluate a – b if a = ¾ and b = 1/6 a – b = ¾ - 1/6 LCD = 12 = 9/12 – 2/12 = 7/12 CONFIDENTIAL
Your Turn • Evaluate c – d if c = 7/8 and d= 3/5 c – d = 7/8 – 3/5 LCD = 40 7/8 – 3/5 = 35/40 – 24/40 = 11/40 CONFIDENTIAL
WORD PROBLEMS How much more is ¾ cup more than 2/3 cup? ¾ - 2/3 = LCD = 12 ¾ - 2/3 = 9/12 – 8/12 = 1/12 CONFIDENTIAL
Your turn • After the school hours, Mr. Bred spend ¾ hours doing mathematics home work. While Miss Peter spend 1/6 hours in doing Science homework. Who spend more time and how much? • Mr. Bred spend more hours • ¾ - 1/6 = 9/12 – 2/12 = 7/12 CONFIDENTIAL
Practice Problems • 2/3 – ½ = 1/6 • 9/10 – ½ = 4/10 • 5/6 – 7/10 = 2/15 • 9/10 – 2/3 = 7/30 • 7/8 – 9/16 = 5/16 CONFIDENTIAL
Review • To find the difference of two fractions with unlike denominators, rename the fractions using the least common denominator (LCD). Then subtract and simplify. CONFIDENTIAL
That’s all for today SEE YOU NEXT TIME CONFIDENTIAL