I will also use oddball units as markers. So if I am doing a high volume of unit A, for every 20 A, I will insert a unit B. it speeds up the counting process. Count the unit B and multiply to get numer of A completed. When I press I cut out the unit B to make smaller kites of 20 A. And I will safety pin completed units together by 20. Anything to avoid counting higher than 100 more than necessary.