This number is then checked against the change in cash reflected on the balance sheet from period to period to verify that the calculation has been done correctly. (entrepreneur.com)
That is, many times I would move — frequently period to period — from a room with one teacher and myself and less than a dozen students to much larger classes. (garyrubinstein.teachforus.org)
Did you find it difficult to switch from period to period? (bookbrowse.com)