Percentage Calculations and Concepts

The video tutorial covers lesson four, focusing on percentage calculations. It includes exercises on calculating the current value of an investment after a decrease, modeling proportional relationships, determining percent increase in badges, estimating original cat population after a decline, and calculating previous test scores from a percentage increase. Students are instructed to fill out a Google form for attendance.

What is the main purpose of watching the video and filling out the Google form?

• To learn new math concepts

• To get points for attendance

• To complete homework

• To prepare for a test

If an investment decreases by 10% from $75, what is the new value?

• $67.50

• $70.00

• $65.00

• $68.00

Which formula is used to calculate the part of a whole in percentage problems?

• Part = Whole / Percent

• Part = Percent + Whole

• Part = Percent x Whole

• Part = Whole - Percent

How do you calculate the remaining value after a 10% decrease?

• Divide the original value by 0.9

• Subtract 10% from the original value

• Add 10% to the original value

• Multiply the original value by 0.9

What is the correct equation for the proportional relationship between original and decreased investment values?

• y = 0.9x

• y = 1.1x

• y = x - 10

• y = x + 10

If Justin earns 2 more badges, what is the percent increase from his original 8 badges?

• 25%

• 20%

• 30%

• 15%

How do you express 10 badges as a percent of 8 badges?

• 75%

• 125%

• 100%

• 150%

If the cat population declined by 30% to 12, what was the original population?

• 20

• 17

• 14

• 15

Lou's test score increased by 25% to 650. What was her score in sixth grade?

• 520

• 500

• 540

• 530