Modeling and Understanding Percents Pages 425-428 in Textbook

Objectives I can use models to represent percents. I can write percents as decimals and fraction.

Vocabulary Percent: Is a ratio that compares a number to 100. The symbol for percent is: %

Modeling Activity On your graph paper make a border to form a 10 x 10 grid. It should contain 100 squares Each of the small squares represents how much? 1/100 or 1% To model 25%, how many squares should I shade in? 25. Go ahead and shade them in.

Continued The shaded portion represents 25%, the decimal 0.25, and the fraction 25/100= ¼ Everyone model 35%. Then write it as a decimal and a fraction. 0.35, 35/100 = 7/20 Try another 80%

Draw Conclusion Reasoning How would I model 100% Shade in 100 squares How would I model 150%? Shade in 150 Squares How would I model 200%? Shade in 200 squares How would I model .5% Shade in half of a square

Understanding Percents A percent is what? A ratio that compares a number to 100. Percents means Per hundred Out of 100 You can remember that percent means per hundred by thinking of how many cents in a dollar.

Writing ratios in different forms. A bag full of 100 marbles, has 43 blue, 7 red and 50 green. You can write the ratio of blue marble to the whole in three ways: Percent: 43% Decimal: 0.43 Fraction: 43/100 Write the ratio of red marbles in the three ways? 7%, 0.07, 7/100

Writing a percent as a decimal! Divide the value by 100: 57% = 57 100 = 0.57 Or you can move the decimal two spots to the left. Try a couple: 15%, 6%, 32.5%

Write a percent as a fraction! Rewrite the percent using a denominator of 100, Simplify if possible. 45% 45/100 = 9/20 You try: 20%, 56%

We will continue with Modeling and Understanding Percents We will continue with Modeling and Understanding Percents. Monday/Tuesday We will be covering percents, decimals, and fractions. Wednesday/Thursday We will be covering the percent of a number.