Question

Convert $\frac{31}{80}$ into decimal.

Answer 1

We can multiply $80$ by $125$ to make it $10000$.

Multiply numerator and denominator by $125$.

$\frac{31\times 125}{80\times 125}=\frac{3875}{10,000}$

Write down $3875$ with the decimal point $4$ places from the right because $10000$ has $4$ zeros.

Hence, the decimal fraction of $\frac{31}{80}$ is $0.3875$.