In order to find the decimals you simply divide the two numbers:
$${\frac{{\mathtt{8}}}{{\mathtt{20}}}} = {\mathtt{0.4}}$$
The decimal is 0.4
If you want to find the precentage you take the decimal and multiply it by 100:
$${\mathtt{0.4}}{\mathtt{\,\times\,}}{\mathtt{100}} = {\mathtt{40}}$$
The percentage is 40%
In order to find the decimals you simply divide the two numbers:
$${\frac{{\mathtt{8}}}{{\mathtt{20}}}} = {\mathtt{0.4}}$$
The decimal is 0.4
If you want to find the precentage you take the decimal and multiply it by 100:
$${\mathtt{0.4}}{\mathtt{\,\times\,}}{\mathtt{100}} = {\mathtt{40}}$$
The percentage is 40%