It's done to keep 2-digit remainder in place without losing it to std::round()

Why do you multiply by 100 and divide by 100?

I was also wondering why is this 5 kyu. I don't know about C++ but in Python it's trivial :)
Anyway, I like this kata :)

It was not my intention to critize the author.
Although I appreciate the potential praise, it was rather meant in a relative way.
I had a similar experience with another Kata and I just found out you wrote it too.
It seems you have an excellent talent for writing Kata's which are really difficult in many languages and are easy in C++ ;).
Thanks for making the Katas, appreciated them nevertheless!

In C++ this can be solved by using a double loop, so 7 kyu or 8 kyu would be more appropiate.

This can't be voted up for being best pratice, it should rather be voted up for being cheating

It is not the author who gives the ranking but a moderator + there are lots of languages in this kata and they are not all with the same problems and difficulty. Moreover maybe you are among the best:-)