convert a fraction to a percent

$8\frac{3}{8}$

$\frac{67}{8}$

$8.375$

$8.375\times100$

837.5%

$\dfrac{1}{8}=12.5\%$

So $8\dfrac{3}{8}=8+\dfrac{1}{8}\times 3=800\% + 12.5\%\times 3=837.5\%$