A town's population of children increased from $376$ to $421$ during the past year.

Find the equation shows how to find the percent increase?

Find the equation that shows how to find the percent increase:

Given that, the population of children increased from $376$ to $421$ during the past year

Step-1. Find the equation.

Use the percentage increase formula:

$\Rightarrow \mathrm{Percentage}\mathrm{increase}=\frac{\mathrm{Final}-\mathrm{Initial}}{\mathrm{Initial}}\times 100$

Substitute the value $\mathrm{initial}=376$ and $\mathrm{final}=421$into the formula:

$\Rightarrow \mathrm{Percentage}\mathrm{increase}=\frac{421-376}{376}\times 100$

Step-2: Simplify the above expression.

$\begin{array}{rcl}& \Rightarrow & \mathrm{Percentage}\mathrm{increase}=\frac{45}{376}\times 100\\ & =& 0.1196\times 100\\ & =& 11.96\%\end{array}$

Hence, the equation that shows how to find the percent increase is $\mathbf{Percentage}\mathbf{}\mathbf{increase}\mathbf{=}\frac{\mathbf{421}\mathbf{-}\mathbf{376}}{\mathbf{376}}\mathbf{\times }\mathbf{100}\mathbf{}\mathbf{=}\mathbf{}\mathbf{11}\mathbf{.}\mathbf{96}\mathbf{\%}$