The Ratio of Oxygen atoms to sulfur atoms in sulfur dioxide is always the same. The table shows different numbers of atoms in different quantities of sulfur dioxide comolete the table

The mole ratio of oxygen to sulfur in sulfur dioxide is equal to 2 oxygen : 1 sulfur. To solve the number of moles of oxygen given the number of mole sulfur multiply is by (2 mole oxygen / 1 mole sulfur. And if you are given the mole oxygen to solve the mole sulfur, multiply the mole oxygen by (1 mole sulfur / 2mole oxygen)