Solving Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the two ratios and then solve for the unknown variable.

Front

If 3 pounds of hamburger costs $6, what is the cost per pound?

Back

The cost per pound is $2.

Front

If 2 slices of pizza have 230 calories, how many calories are in 1 slice?

Back

115 calories.

Front

What is the formula to find the total cost for a given quantity based on a unit price?

Back

Total Cost = Unit Price x Quantity.

Front

How do you set up a proportion to find an unknown value?

Back

Set up the proportion by creating a ratio of known values and equating it to a ratio that includes the unknown.

Front

What is the relationship between the number of people and the cost of tickets in a proportional situation?

Back

As the number of people increases, the total cost increases proportionally.

Front

If 6 people pay $39 for tickets, what is the cost per person?

Back

The cost per person is $6.50.

Front

How do you find the total cost for 9 people if 6 people cost $39?

Back

Use the unit cost: $39/6 = $6.50 per person; then multiply by 9: $6.50 x 9 = $58.50.

Front

What is the cross-multiplication method in solving proportions?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio and setting the two products equal.