"Following the breath while counting (breath-counting) is simply counting 1 to 10, which can be exhalations (most typically), inhalations, or even both (1 on inhalation, 2 on exhalation, 3 on inhalation, etc.). The idea is to keep returning to 1, and notice where you mind was. If you get to where you can't remember whether it was 5 or 6, return to 1. If you get to 35 or 47 (the mind having gone off on its own parallel track)—return to 1. Again, that noticing is the point of perfect awareness."
This quote is taken from an interview with Genko Rainwater at MeditationHow.info.
This six part meditation testimonial and interview features Genko Rainwater who speaks on Shikantaza Meditation, Breath Counting Practice in Meditation, Following the Breath, Kindness and Compassion, Meditation Teachers, and Zen Buddhist Meditation Experiences.