Density, Percentages, and Growth Problems

This video tutorial teaches how to solve for unknown percentages using various methods: bar model, table, and proportion. It includes examples such as calculating gratuity, height increase, and density percent error. The tutorial emphasizes understanding the relationship between numbers and percentages, and choosing the appropriate method based on the problem's complexity.

Which method is considered more flexible for solving unknown percentages?

• Graph

• Table

• Proportion

• Bar model

If a dinner bill is $12 and the gratuity is $4, what is the percentage of the gratuity?

• 33.33%

• 25%

• 50%

• 66.67%

What is the first step in using a bar model to solve for an unknown percentage?

• Identify the whole as 100%

• Subtract the smaller number from the larger

• Multiply the parts by 100

• Divide the total into equal parts

How much did Henry's height increase in inches?

• 22 inches

• 16 inches

• 18 inches

• 20 inches

What percentage increase corresponds to an 18-inch growth in Henry's height?

• 35%

• 37%

• 36%

• 34%

In the context of the video, what does a unit rate help determine?

• The original amount

• The total increase

• The percentage per unit

• The total percentage

What was Bianca's reported density of a nickel?

• 6.44 grams per milliliter

• 6.59 grams per milliliter

• 5.59 grams per milliliter

• 5.44 grams per milliliter

What is the actual density of a nickel according to the video?

• 6.59 grams per milliliter

• 5.44 grams per milliliter

• 6.44 grams per milliliter

• 5.59 grams per milliliter

What is the percent error in Bianca's measurement of the nickel's density?

• 12.2%

• 13.2%

• 14.2%

• 15.2%

Which method is used to solve for percent error in the density example?

• Bar model

• Graph

• Table

• Proportion