Decimals Fractions Percents

Fraction ↔ Decimal Review To write a fraction ( 4 5 ) as a decimal: Divide  4 ÷ 5 = 0.8 To write any decimal as a fraction, just use place value 6 10 a) 0.6 b) 0.53 c) 0.235 there is a 6 in the tenths place 53 100 there is a 53 in the hundredths place 235 1000 there is a 235 in the thousandths place

The word percent means “per hundred” So, a percent is a ratio of a number to 100. Which means 25% is “25 out of 100”

32 75 ___ ___ 100 100 Modeling Percents Write the percent modeled by each grid. A. B. 32 100 ___ 75 100 ___ shaded total _______ shaded total _______ = 32% = 75% 4

Writing Percent as Decimals Write 17% as a decimal. Method 1 Write the percent as a fraction with a denominator of 100. 17 100 17% = = 0.17 Divide 17 by 100. Method 2 Use mental math. 17% = 0.17 Move the decimal point two places to the left. (÷ 100%)

Writing Decimals as Percent Write .005 as a percent. Method 1 Fraction Form 5 1000 5 is in the Thousandths Move the decimal to get it out of 100 = 0.5 100 = 0.5% Method 2 Use mental math. Move the decimal point two places to the right. (x 100%) .005 = 0.5%

divide   ÷100  hundredths place x 100 

Write each percent as a decimal and as a fraction 1. 𝟗% 2. 𝟒.𝟐𝟓% = 𝟒.𝟐𝟓 𝟏𝟎𝟎 move decimal = 425 10000 =𝟎.𝟎𝟒𝟐𝟓 (425 ten thousandths) = 𝟗 𝟏𝟎𝟎 ÷25 = 𝟏𝟕 𝟒𝟎𝟎 =𝟎.𝟎𝟗 (9 hundredths)

Finding a Percentage Find 28% of 690 28% = 0.28 “of” means multiply So 28% of 690 is 0.28 x 690 = 193.2 Must change percentage to a decimal first

Finding a Percentage 0.55 x 120 = 66 boys 55% of 120 children at the cinema were boys, how many were boys? Convert 55% to decimal first 0.55 x 120 = 66 boys

Classwork Page 246-247 # 5,6,10a, 11a (no diagrams or number line required) 12a