What is the connection between ratios, fractions, and percents? Intro to Percents

Percents Cent means one hundred, so what do you think percent means?

Percents as ratios A percent is a part-to-whole ratio where the whole is % = n% = n_ 100

Examples Write 35% as a fraction in simplest form.

Examples Write 100% as a fraction.

Examples Write 174% as a fraction in simplest form.

What if there is a decimal in the percent? 17.5 % 0.25%

Writing Fractions as Percents Write an equivalent fraction with a denominator of 100. Then write the numerator with a percent symbol. Write 3 as a percent. 50

Write each fraction as a percent.

Application A drought affects 9/12 of the Midwestern states. What percent are affected by the drought?

Conclusion What is the connection between ratios, fractions, and percents? Add in headings and questions.

What is the connection between decimals, fractions, and percents? Using Decimals with Percents

Review converting percents and fractions Convert 4to a percent. 5 Convert 52% to a fraction.

How are percents and decimals related? See if you can develop a relationship = 25= 25% % = 14 =

What is the relationship? Decimal to percent – Move decimal point two places to the right = ______% Percent to decimal – Move decimal point two places to the left. 65% = _______

Converting with all three: percents, fractions and decimals Decimal Fraction 45% = _______ = ________ Percent Decimal 13 = _______ = ________ 20 Percent Fraction 0.15 = _____ = ________

If you know one form of a ratio, you can convert to the other two forms. FractionPercentDecimal %

Conclusion What is the connection between decimals, percents, and fractions?

How can you use mental math, number lines, and proportions to find the percent of a number? Finding Percents of Numbers

Activity 1

Additional Practice Put in notes What is 60% of 90? What is 30% of 150?

Solve those problems using proportions 60% of 90 30% of 150

More examples 1)90% of 20 2)75% of 32 3)150% of 12

Day 2 Review Remember to find 10% of a number, simply move the decimal point in 1 place to the left. To find 1% of a number, move the decimal point 2 places to the left. Find 10% of x 30 = 3 Find 1% of x 30 =.3

Review of using mental math Find 60% of 90.

Review of using mental math Find 40% of 150.

Would you rather?

20% off or $20 off???? These shoes are $40. Would you rather use a $20 coupon or get 20% off the price. Show me both answers.

20% off or use a $20 coupon. This television sells for $1200 on Black Friday.

Conclusion How can you use proportions to find percents of numbers?

How can you find the whole when given the part of a percent? More Percent Proportions

75% of what number is 48 Put 48 under 75. In groups, complete the number line to figure out what 100% is.

120% of what number is 72. Put 72 under 120%. Now divide 72 by 12. This will tell you what 10% is. 110% 120%

How else can you find the whole? Can you use the percent proportion? Is = % of100 5% of what number is 10?

62% of what number is 31 Use the percent proportion.

Put in your notes 25% of what number is % of what number is 35

Word Problem 54% of the 6 th grade students at Utt Middle School are girls. If there are 162 girls, how many total students are there? How many boys are there?

Conclusion How can you find the whole when given the part of a percent?