7th Grade Unit 4 Review

Front

What is a percentage increase?

Back

A percentage increase is a way to express how much a quantity has grown compared to its original amount, calculated as (new value - original value) / original value * 100.

Front

How do you calculate the original amount from a percentage increase?

Back

To find the original amount when given a new amount and a percentage increase, use the formula: original amount = new amount / (1 + percentage increase as a decimal).

Front

What is a percentage decrease?

Back

A percentage decrease is a way to express how much a quantity has decreased compared to its original amount, calculated as (original value - new value) / original value * 100.

Front

How do you calculate the new amount from a percentage decrease?

Back

To find the new amount when given an original amount and a percentage decrease, use the formula: new amount = original amount * (1 - percentage decrease as a decimal).

Front

What is the formula to find the total after a percentage increase?

Back

Total after percentage increase = original amount * (1 + percentage increase as a decimal).

Front

What is the formula to find the total after a percentage decrease?

Back

Total after percentage decrease = original amount * (1 - percentage decrease as a decimal).

Front

If a class has 30 students after a 15% increase, how many students were there originally?

Back

30 = 1.15x, where x is the original number of students. Therefore, x = 30 / 1.15 = 26.09, approximately 26 students.

Front

How do you find the length of an object that is a certain percentage longer than another?

Back

Length of the longer object = length of the original object * (1 + percentage increase as a decimal).

Front

If a car is 180 inches long and a truck is 75% longer, how long is the truck?

Back

Truck length = 180 * (1 + 0.75) = 180 * 1.75 = 315 inches.

Front

What does it mean if a price is marked down by a percentage?

Back

A price marked down by a percentage means that the new price is lower than the original price by that percentage.