idk why I'm replying to a 10mo old comment but @Keasaer I don't think it's unrealistic at all tbh. In highschool phys there are plenty of questions on kinematics, so memorising that you can convert from km/hr to m/s by dividing by 3.6 is pretty normal. And the estimation is also pretty realistic...
@WM46 One of the majikoi vn's (can't tell u specifically since I've only played one, but you can see all the games the jun guy is in here: https://vndb.org/c9794