The problem, however, was that the pupils did not notice this fact for both denominators, and thus they multiplied them together and then calculated large numbers. The first example after adjusting the pupils looked like this 154/605> 165/605. This procedure is not bad, but it is more time and numerically demanding. Pupils thus count large numbers unnecessarily. The pupils managed the second example without any difficulties.
The first example after adjusting the pupils looked like this 154/605> 165/605.