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Fractions and Decimals. Lesson 5-5 (Glencoe) Unit 1: Comparing and Ordering Positive Rational Numbers and Integers ( Cscope ). TEKS 7.1 B.
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Fractions and Decimals Lesson 5-5 (Glencoe) Unit 1: Comparing and Ordering Positive Rational Numbers and Integers (Cscope)
TEKS 7.1 B • 7.1 Students represent and use numbers in a variety of equivalent forms. (B) convert between fractions, decimals. Whole numbers, and percents mentally, on paper, or with a calculator
Writing Fractions as Decimals • What fraction of he buildings are between 600 and 800 feet tall? • Express this fraction using words and then a decimal. • The table shows the heights of the ten tallest buildings in Dallas. 8 10
Express this fraction using words and then a decimal. When the denominator of a fraction is a power of 10, use place value to write the fraction as a decimal 8 10
Now you try… • What fraction of buildings are between 710 and 850 feet tall? • Express this fraction using words and then as a decimal.
What have we learned so far? • When a denominator of a fraction is a factor of 10, 100, 1000 you can use mental math. • Name some factors of: • 10 • 100 • 1000
Examples of using Mental Math: • Write each fraction or mixed number as a decimal. • 7 THINK So, 7 x 5 = 0.35 20 20 7 35 20 100 x 5 • 5 ¾ • Think of the mixed number as a sum = 5 + ¾ • You know ¾ = 0.75 so, = 5 + 0.75 • Add mentally = 5.75 • So, 5 ¾ = 5.75
Check Your Progress • 3/10 • 3/25 • 6 ½ = 0.3 = 0.12 = 6.5
Any fraction can be written as a decimal by dividing its numeratorby its denominator. Division ends when the remainder is zero. • Write 3/8 as a decimal. • Denominator outside • Numerator inside the division icon . 7 5 0 3 8 3 0 0 0 -24 0 6 - 5 6 4 0 - 4 0 0 Division ends when the remainder is zero
Check Your Progress • 7/8 • 2 1/8 • 2/3 • 8 1/3 = 0.875 = 2.125 = 0.66 = 8.33
Putting it to Practice • Glencoe page 247 • 1-11 (odd and check your answers on pg. 296) • 13 - 43 (all) • 46 (if you cannot figure out the answer, write down your thoughts)