Percent Change (NEW value)

Percent Change (NEW value)

Aim: How do we determine the new value in a percent change problem?

Make sure to have a notebook in front of you to take notes to upload as your exit ticket for the day!

Percent Change

 $\frac{quantity\ of\ change}{original}=\frac{new-original}{original}$  

Open Ended

Do Now:

1. In the Bronx, the average low temperature for January was 28 °F. The average low in February was 36 °F. What was the percent of increase in the Bronx's average low temperature?

2. What is the percent change from 36°F to 28°F?

3. Is the percent change the same for question 1 and 2? Why or why not?

Multiple Choice

What is the percent of change? 18.7 kg to 4.5 kg

• 76% increase

• 3% increase

• 76% decrease

• 3% decrease

Finding the New Value in a Percent Change Problem

• Step 1: Determine whether the change is an increase (+) or decrease (-)

  
  

• Determine the Original Amount and the New Amount

• Solve for the unknown by substituting in values into the equation and isolating the variable

   $decimal=\frac{new-original}{original}$  

Matthew is trying to drink more water, so he has been keeping a log of how much water he drinks. Matthew drank 46 ounces of water two days ago. Yesterday, he drank 50% less. How much water did he drink yesterday?

Multiple Choice

A gardening store ordered 5,710 potted plants last year. This year, the store ordered 20% fewer potted plants. How many potted plants were ordered this year?

• 4568 potted plants

• 6852 potted plants

Open Ended

Why does 6852 potted plants not make sense as an answer to the last question?

Multiple Choice

A generation ago, the graduating class at Fairfax High School was 150 students. This year, it is 54% larger. What is the current size of the graduating class?

• 69 students

• 231 students

Open Ended

Why does 69 students not make sense as an answer to the last question?