$${\frac{{\mathtt{5}}}{{\mathtt{8}}}} = {\mathtt{0.625}}$$ ; $${\frac{{\mathtt{12}}}{{\mathtt{25}}}} = {\mathtt{0.48}}$$ ; $${\frac{{\mathtt{5}}}{{\mathtt{6}}}} = {\mathtt{0.833\: \!333\: \!333\: \!333\: \!333\: \!3}}$$
Simply divide the numerator by the denominator and it will be in decimal form
For example if i wish to convert 7/8 to decimal form i will perform the following: Seven divided by eight = .875
$${\frac{{\mathtt{5}}}{{\mathtt{8}}}} = {\mathtt{0.625}}$$ ; $${\frac{{\mathtt{12}}}{{\mathtt{25}}}} = {\mathtt{0.48}}$$ ; $${\frac{{\mathtt{5}}}{{\mathtt{6}}}} = {\mathtt{0.833\: \!333\: \!333\: \!333\: \!333\: \!3}}$$