Percent of Change / Percent of Error

Front

What is Percent of Change?

Back

Percent of Change is a way to express how much a quantity has increased or decreased in relation to its original amount, calculated as (New Value - Original Value) / Original Value x 100%.

Front

What is Percent of Error?

Back

Percent of Error is a measure of how inaccurate a measurement is, expressed as a percentage of the true value, calculated as |Estimated Value - Actual Value| / Actual Value x 100%.

Front

How do you calculate Percent of Change?

Back

Percent of Change = (New Value - Original Value) / Original Value x 100%.

Front

How do you calculate Percent of Error?

Back

Percent of Error = |Estimated Value - Actual Value| / Actual Value x 100%.

Front

If a product's price decreases from $60 to $50, what is the percent of change?

Back

Percent of Change = (50 - 60) / 60 x 100% = -16.67% (a decrease).

Front

If a student estimates they can run a mile in 8 minutes but actually takes 10 minutes, what is their percent of error?

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Percent of Error = |8 - 10| / 10 x 100% = 20%.

Front

What does a positive percent of change indicate?

Back

A positive percent of change indicates an increase in value.

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What does a negative percent of change indicate?

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A negative percent of change indicates a decrease in value.

Front

If a student thinks there are 30 students in a class but there are actually 25, what is the percent of error?

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Percent of Error = |30 - 25| / 25 x 100% = 20%.

Front

What is the formula for finding the actual value if you know the estimated value and percent of error?

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Actual Value = Estimated Value / (1 - Percent of Error/100).