C++ Rounding random double

New to coding and C++.
I'm having some issues with sorting out a random double to be only one decimal point. I've given it a look online and, from what I can tell and understand, I've got everything correct. Obviously not, however. Specifically, it appears that I may be using 'round()' incorrectly because, even when I don't do all the other multiplication (etc) to it, it doesn't round the double.

double u;
srand(unsigned(time(NULL)));

for(int i = 0; i < 10; i++){
    u = (double)rand()/(RAND_MAX+1) + (rand()%101); //Acquire random number, turn it into decimal and then add it to another number between 0-100.
    u *= 10; //Shift numbers left to remove first decimal from round.
    round(u); //Round to nearest whole number.
    u /= 10; //Shift right to return the first decimal.

    cout<<u<<" "<<flush;
}

This method seems terrible to me. Obviously it won't work up at the higher reaches of double (since *10 might overload it, or whatever it's called). If someone could:
A) Show me where I went wrong with this code or, alternatively, hint it.
B) Suggest a better, more efficient way of doing this. As I'm sure there definitely is one.
C) Ability to round to decimal points other than the 1st.

Thanks and much appreciated in advance!