Confused about oxidation number

[calios]

guys anyone can help me ?
im bit confused when talkin about oxidation number in alkyl group
like
R-NO₂
or
R-CN
when this compound react with reducing agent like H₂
can somebody explain me? most example in book or internet doesn't use hydrocarbon reaction
thank you :)

 

[Borek]

Oxidation number of what?

 

[calios]

oxidation number of R (alkyl) so its relate calculation with other

 

[Borek]

Does it matter? It doesn't change during reduction of -NO₂ or -CN.

Please remember that oxidation numbers don't exist - there is no physical property that can be measured and used to determine the ON, they are just an artificial accounting device.