Percent and Scale Factor Review

Front

What is the formula to calculate a percentage?

Back

Percentage = (Part / Whole) × 100

Front

What is 20% of 75?

Back

15

Front

How do you find the total amount if you know a percentage of it?

Back

Total = Part / (Percentage / 100)

Front

Michael spent $210 on school supplies and books. This amount was 30% of his savings. How much was his savings?

Back

$700

Front

What is percent error?

Back

Percent Error = |Estimated Value - Actual Value| / Actual Value × 100

Front

Ms. Brown estimated 70 students would try out for the Cross Country team. This year, only 63 students tried out. What was her percent error?

Back

11%

Front

What is the formula for percent change?

Back

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

Front

Mary lost 30 pounds. Before her diet she weighed 180 pounds. What is the percent of change?

Back

17% Decrease

Front

What does scale factor mean in geometry?

Back

Scale factor is a number that scales, or multiplies, some quantity.

Front

If the scale factor is ½, what does it indicate?

Back

Reduction