Forgot To Take Generic Version Of Concerta This Morning. Too

Forgot to take Generic version of Concerta this morning. Too late to take it now (4pm). Can I split it in half? Not sure if that would mess up the Extended release process, but curious. I usually have a 10mg methylphenidate tab available for days like this, but forgot to request refill. (30 tabs can last me two years, so I forget about them until I'm bumbling around like Mr. McGoo wondering why I can't get myself in the groove...like now! Have a deadline and need to FOCUS.