$${\frac{{\mathtt{6}}}{{\mathtt{9}}}} = {\frac{{\mathtt{2}}}{{\mathtt{3}}}} = {\mathtt{0.666\: \!666\: \!666\: \!666\: \!666\: \!7}}$$
You could leave it at 2/3.
To simplify, find a number which will divide both the top and bottom numbers evenly. In this case it is 3.
