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 The table shows the heights of the ten tallest buildings in Dallas. Building Height (ft) Bank of America Plaza 921 Renaissance Tower 886 Bank One Center 787 JP Morgan Chase Tower 738 Fountain Place 721 Trammell Crow Center 686 1700 Pacific Avenue 655 Thanksgiving Tower 645 Energy Plaza 629 Elm Place 625 What fraction of he buildings are between 600 and 800 feet tall? Express this fraction using words and then a decimal. 8 10

Express this fraction using words and then a decimal. 8 10 When the denominator of a fraction is a power of 10, use place value to write the fraction as a decimal Words eight tenths Model Fraction 8/10 Decimal 0.8

Now you try… Building Height (ft) Bank of America Plaza 921 Renaissance Tower 886 Bank One Center 787 JP Morgan Chase Tower 738 Fountain Place 721 Trammell Crow Center 686 1700 Pacific Avenue 655 Thanksgiving Tower 645 Energy Plaza 629 Elm Place 625 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 7 20 35 100 x 5 = 0.35 20 20 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 numerator by its denominator. Division ends when the remainder is zero. Write 3/8 as a decimal. Denominator outside Numerator inside the division icon . 3 7 5 8 3 -24 6 - 5 6 4 - 4 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)