The big number counting is shown/hidden using the first fader in the mixer.
You can toggle the mixer using the middle of the 3 buttons under the play button.
When the Big # fader is at 0% you won't see big numbers.
When it's between 1% and 99% you'll see big numbers above the metronome and will still be able to tap the metronome buttons.
When it's at 100% you'll see big numbers on a black background. Tapping anywhere on the screen will stop PolyNome.