7.RP.A.3 - Finding PercentsUse proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.
Students know they can always find one percent of a quantity by dividing it by 100 or multiplying it by 1/100, and they also know that finding 1% first allows them to then find other percents easily. For instance, if students are trying to find the amount of money after 4 years in a savings account with an annual interest rate of 12% on an account balance of $300, they use the fact that 1% of 300 equals 300100, or $3, thus 12% of 300 equals 12 of $3, or $1.50. $1.50 multiplied by 4 is $6 interest, and adding $6 to $300 makes the total balance with interest equal to $306.
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Due 11/23
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