Unit 4: Test Review

Front

What is the formula to calculate percent change?

Back

Percent Change = (New Value - Old Value) / Old Value * 100

Front

If a stock is bought for $15 and sold for $20, what is the percent increase?

Back

Increase of 33.3%.

Front

How do you calculate the cost of multiple items based on a unit price?

Back

Cost = (Number of Items) * (Cost per Item). For example, if 3 apples cost $9.99, then 4 apples cost $13.32.

Front

What is percent error and how is it calculated?

Back

Percent Error = (Estimated Value - Actual Value) / Actual Value * 100.

Front

If you estimate sending 135 texts but actually sent 108, what is the percent error?

Back

Percent Error = (135 - 108) / 108 * 100 = 25%.

Front

What does it mean to increase a quantity by a percentage?

Back

To increase a quantity by a percentage, multiply the original quantity by the percentage (as a decimal) and add it to the original quantity.

Front

If a band writes 75% more songs than they expect to put on a CD, how do you calculate the total number of songs written?

Back

Total Songs Written = Expected Songs + (Expected Songs * 0.75). If they expect 16 songs, they write 28 songs.

Front

What happens to the total number of songs if 50% are removed during editing?

Back

Total Songs After Editing = Total Songs Written - (Total Songs Written * 0.50). If 28 songs were written, 14 remain.

Front

How do you maintain the same ratio when scaling a mixture?

Back

To maintain the same ratio, multiply each component by the same factor. For example, if the ratio of red to yellow paint is 3:7, and you have 35 teaspoons of yellow, you need 15 teaspoons of red.

Front

What is a double number line diagram and how is it used?

Back

A double number line diagram visually represents two related quantities, helping to find equivalent ratios or solve problems involving proportions.