# Oxidation of methane

In the reaction $\ce{CH_4 + 2O_2->CO_2 + 2H_2O}$ the $\ce{C}$ atom is oxidized. I can clearly see the addition of $\ce{O}$ atoms, however I don't see a change in Oxidation state. In the products, $\ce{C}$ oxidation state (O.S) was +4, and in the reactants, $\ce{C}$ O.S is +4. I believed an oxidation meant an increase in oxidation state. What am I missing?

Actually in $\ce{CH4}$ with slightly more electronegtaive carbon it is in $-4$ state. With $\ce{CO2}$ the oxygen is more electronegative oxygen carbon is $+4$. Therefore oxidation is also defined as addition/replacement of a more electronegative element.
Electronegativities $$\begin{array}{}\bf H&2.2\\\bf C&2.55\\\bf O&3.44\end{array}$$