Number Sense 14 Percentages 数感14百分比.pptVIP

Holt CA Course 1 6-1 Introduction to Percents Learning Objective: We will calculate1 percentages. 1solve, compute NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips. California Standards Pre-pronounce, choral read, What are we learning today? PS, 2x Warm Up Write each fraction as a decimal. 1. 3 4 3 8 2. 0.75 0.375 APK: Teacher models one, students WB second Vocabulary percent A percent is a ratio of a number to 100. The symbol % is used to indicate a percent. The word percent means “per hundred.” So 6% means “6 out of 100.” Reading Math Pre-pronounce, choral read, What is % PS, 2x Concept 6 100 = 6% example Notice the 10 x 10 square grid. There are 100 total squares. Six of the squares are colored. Six red squares of 100 total squares can be shown like this: Which of the following is an example of a percent? 32% A B 76 How do you know that? PS 3x Importance You need to know how to calculate percent *to do well on the CSTs and benchmarks *to calculate your savings on purchased items *to calculate interest on borrowed money Here’s a sample release question… Write the percent modeled by each grid. A. B. Example 1: Modeling Percents shaded total _______ 32 100 ___ = 32% shaded total _______ 75 100 ___ = 75% I do: How did I determine the percent modeled? We do Write the percent modeled by each grid. A. B. Check It Out! shaded total _______ 44 100 ___ = 44% shaded total _______ 66 100 ___ = 66% I do: How did I determine the percent modeled? We do Write the percent modeled by each grid. A. B. You do How did you determine the percent modeled? PS 3x 28% 43% shaded total _______ Write 28% as a fraction in simplest form. Writing Percents as Fractions So 28% can be written as . Write the percent as a fraction with a denominator of 100. Simplify. 28% = 28 100 7 25 = 7 25 Variation 2 I do: What did I do to make 28%