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December 19, 2012 Please get out a pencil and your notes journal , and clear your desk . Please be ready as soon as the bell rings !!!!. Ratio Quiz Bonus Question. There are 36 students on the soccer team. The ratio of boys to girls is 2:7. How many boys are on the team? .
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December 19, 2012Please get out a pencil and your notes journal, and clear your desk. Please be ready as soon as the bell rings!!!!
Ratio Quiz Bonus Question • There are 36 students on the soccer team. The ratio of boys to girls is 2:7. How many boys are on the team?
Unit Rate • Unit rate is a ratio comparing something to one of another. • Examples: • miles per hour • Miles per gallon • Dollars per hour • Words per minute • You find the unit rate by setting up a ratio and dividing by the bottom number in the ratio.
Proportion • A proportion is two equivalent ratios. • Example: 2 girls to 3 boys = 6 girls to 9 boys • Example: 9 blue to 7 red =90 blue to 70 red You solve a proportion by figuring out what was done to the top or bottom and find the equivalent ratio(fraction)
Percents • A percent means out of 100. (Just a fraction over 100) • To determine the fraction, you put the percent over 100, then reduce to simplest form. • To convert to a percent from a fraction you form a proportion with the fraction equal to x over 100. • Ex: 23% = 23/100 • Ex: 2/5 = x/100
Changing from a decimal to a percent • Read the decimal. Ex: 0.57 is read as fifty seven hundredths. • Write the decimal as a fraction. Ex: fifty seven hundredths is written as • Set up the proportion from the fraction to percent. Ex: • Solve the proportion. Ex:
Changing from a percent to a decimal • Write the percent as a fraction over 100. Ex: 20% = • Read the fraction. is read as twenty hundredths. • Write the decimal that is the same as what you read. Ex: twenty hundredths is written as 0.20.