SME
Grade 7 Math
Ratios & Proportions
Proportional relationships and the constant of proportionality
Main lesson
Solve a proportion
Use this for “If 3/20 = n/300, what is n?” and “450 g of oats makes 12 bars; how much for 20 bars?”
Rates with fractions
Use this for “1/2 cup of sugar for every 3/4 cup of flour: how much sugar for 1 cup of flour?”
Proportional or not?
Use this for “Does the table show a proportional relationship?” or “Is y = 2x + 1 proportional?”
Tax, tip, markup, discount and percent change
Main lesson
Discount and sale price
Use this for “A $64 coat is 30% off. What is the sale price?”
Percent increase and decrease
Use this for “The price went from 50¢ to 60¢. What is the percent increase?” or “After a 25% increase it costs $50. What was the original price?”
Percent error
Use this for “A kitchen scale reads 245 g for a 250 g weight. What is the percent error?”
Simple interest
Use this for “$500 at 4% a year for 3 years: how much interest?”
Tax, tip, markup, discount or commission?
Use this for “Is it a markup or a discount?” before working out the percent.