On-the-bike math: share your best anecdote

I usually try to calculate how many calories i should burn with this interval or workout. It also motivates me to calculate calories burned per second when i am doing tough intervals:) 330W means 20 Cals per minute which is insane.

Another trick i use is trying to calculate my average power at the end of intervals, and bu the end of the workout how dumb i become even for simple math:)