C₆H₁₂O₆ + O₂ ⇄ CO₂ + H₂O
There are 6 carbons on the left side, so you need at least 6 molecules of CO₂ on the right.
You also have 12 hydrogens on the left, so you need at least 6 molecules of H₂O on the right.
The reaction so far is then
C₆H₁₂O₆ + O₂ ⇄ 6 CO₂ + 6 H₂O
Now, on the left, you have a total of 6 + 2 = 8 oxygens, while on the right, you have 12 + 6 = 18 oxygens. To make up the difference, you need 6 molecules of oxygen:
C₆H₁₂O₆ + 6 O₂ ⇄ 6 CO₂ + 6 H₂O
so the sequence is 1, 6, 6, 6.
