On-the-bike math: share your best anecdote

I focus on pedal revolutions. I do 100 groups of 3 revolutions counting off the right foot and then 100 off the left. I focus on form and only let my concentration drop when I know the interval will be over before the next 100 finishes. For some reason it has to be groups of 3. I tried 2 and 4 but it just wasn’t floating my boat.