Percent Change / Simple Interest

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What is percent change and how is it calculated?

Back

Percent change is a measure of how much a quantity has increased or decreased relative to its original value. It is calculated using the formula: Percent Change = ((New Value - Old Value) / Old Value) * 100.

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How do you calculate the sales tax on a purchase?

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To calculate sales tax, multiply the total purchase amount by the sales tax rate (expressed as a decimal). Sales Tax = Purchase Amount * Sales Tax Rate.

Front

What is the formula for calculating simple interest?

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The formula for calculating simple interest is: Interest = Principal * Rate * Time, where Principal is the initial amount, Rate is the interest rate (as a decimal), and Time is the duration in years.

Front

If a product's price decreases from $12 to $8, how do you find the percent of change?

Back

To find the percent of change, use the formula: Percent Change = ((New Price - Old Price) / Old Price) * 100. In this case, Percent Change = ((8 - 12) / 12) * 100 = -33%.

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What does a 20% increase in salary mean in terms of calculation?

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A 20% increase means that the new salary is 120% of the original salary. To calculate the new salary, multiply the original salary by 1.20.

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How do you convert a percentage to a decimal?

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To convert a percentage to a decimal, divide the percentage by 100. For example, 8.25% as a decimal is 0.0825.

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What is the significance of the principal amount in simple interest calculations?

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The principal amount is the initial sum of money on which interest is calculated. It is crucial because the interest earned is directly proportional to the principal.

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How do you determine the total cost of an item including sales tax?

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To determine the total cost including sales tax, add the sales tax to the original price: Total Cost = Original Price + Sales Tax.

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What is the difference between percent increase and percent decrease?

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Percent increase measures how much a value has grown relative to its original value, while percent decrease measures how much a value has fallen relative to its original value.

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How do you find the interest earned over multiple years using simple interest?

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To find the total interest earned over multiple years, use the formula: Total Interest = Principal * Rate * Time. For example, for 5 years at 5% on $500, Total Interest = 500 * 0.05 * 5 = $125.