So, to concentrate at the start of each level it might be more appropriate to say: 'We're getting in synch!' It should be emphasized at this point that this is not a question of counting off the seconds. What appears initially to be pure luck, becomes a real 'skill' after playing for a while. Over the course of the game, the players become increasingly synchronized in terms of their sense of time, so they get better and better at estimating how much time needs to pass before playing a particular number card.
A 5 would be played pretty swiftly, whereas an 80 is likely to be held in the player's hand for a while. The lower a card is, the earlier it will be played. The Mind is a game of synchronization which relies on your sense of time.