  Since Aristotle (esp. Metaphysics x.1-2) treats measurement under his discussions of units (and hence number), it turns out that the precision problem becomes a problem of sorting out precise units of measure. Hence, in the case discrete quantities, such as cows, the unit is very precise, one cow. In the case of continuous quantities, the most precise unit of time is the time it takes for the fixed stars (the fastest things in the universe) to move the smallest perceptible distance. But a point or indivisible with position removed or a cow qua unit, i.e., a mathematical unit, is precise. 