Percentage and Decimal Review: Videos & Practice Problems

To calculate percentage change, use the formula: $\frac{(\mathrm{New\; Value}-\mathrm{Original\; Value})}{\mathrm{Original\; Value}}$. For example, if sales revenue increased from $550,000 to $800,000, the change is $250,000. Dividing this by the original value gives 0.45, which converts to 45% when moved two decimal places to the right. Understanding percentage change is crucial for analyzing economic trends and market performance.

The formula for percentage change is: $\frac{(\mathrm{New\; Value}-\mathrm{Original\; Value})}{\mathrm{Original\; Value}}$. This formula helps you determine the relative change between two values, expressed as a percentage. For instance, if the original value is 10 and the new value is 15, the percentage change is $\frac{(15-10)}{10}$ = 0.5 or 50%.

To convert a decimal to a percentage, move the decimal point two places to the right and add a percentage sign (%). For example, if you have a decimal value of 0.45, moving the decimal two places to the right gives you 45. Therefore, 0.45 as a percentage is 45%.

To find the percentage change, use the formula: $\frac{(\mathrm{800,000}-\mathrm{550,000})}{\mathrm{550,000}}$. The change is $250,000. Dividing this by the original value of $550,000 gives approximately 0.4545. Converting this decimal to a percentage by moving the decimal point two places to the right gives 45.45%. Therefore, the percentage change is 45.45%.

Understanding percentage change is crucial in economics because it allows analysts to measure the relative change in economic variables over time. This helps in comparing different periods, assessing growth rates, and making informed decisions. For example, knowing the percentage change in sales revenue can help businesses evaluate their performance and strategize for future growth.