When counting by ones, what type of questions should be asked?

When counting by ones, the fundamental concept is to incrementally increase the number by one at each step. Asking "What number is 1 larger than the last?" directly relates to this incremental increase. It reinforces the idea of sequential counting and helps to solidify the understanding of the counting process. This type of question encourages students to think of the next number in a growing sequence and helps with their numerical fluency.

The other options involve different mathematical concepts that do not pertain to counting by ones. For example, computing products or fractions requires a different set of operations that complicate the simple act of counting. The notion of square roots also introduces advanced mathematics that goes beyond the basic counting skills needed when focusing on counting by ones. Thus, option A is the most appropriate for the context of counting by ones.