In France, in science we had to answer with the same number of digit after the decimal point as given in the exercise. It didn't feel right to me when that was

In France, in science we had to answer with the same number of digit after the decimal point as given in the exercise. It didn't feel right to me when that was crunched through logs and sine, but I got nowhere when I brought it up to the teacher. And even now the whole premise is flawed to me, because it's about significant digits, not just the number of figures after the decimal point, if you compute a times ten you have to remove one digit after the decimal point.