Counting pot odds while mult-tabling

[idxox]

I'm curious how you guys count pot odds while playing on more than one table. When you're playing more than one table, you can't sit around and count each bet as it goes around, so I find myself constantly doing math dividing the pot by the limit, and my arithmetic isn't really that quick.

Is there any special tactic that you use or have you been playing the same limit for so long that you pretty much know the math?

Thanks