7th grade Ratio and Proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

What does it mean for a table to be proportional?

Back

A table is proportional if the ratios of the corresponding values are constant.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the values and then divide to find the unknown.

Front

If I eat 2/5 of dinner in 1/7 hour, how do I find out how much I eat in one hour?

Back

Multiply the amount eaten by the reciprocal of the time taken: (2/5) * (7/1) = 14/5 = 2 4/5.

Front

What is the formula to find the cost per person?

Back

Cost per person = Total cost / Number of people.

Front

If 6 people pay $39, how much do 9 people pay?

Back

Set up a proportion: 6/39 = 9/x, solve for x to find that 9 people pay $58.50.

Front

What is a proportion?

Back

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

Front

How do you find the missing value in a proportion?

Back

Use cross-multiplication to find the missing value.

Front

What is the relationship between ratios and fractions?

Back

Ratios can be expressed as fractions, showing the same relationship between two quantities.

Front

What does it mean to scale a ratio?

Back

Scaling a ratio means multiplying both parts of the ratio by the same number to maintain the same relationship.