How to round float in C without using printf()

Question

I’m not getting round the float to the first two decimal places.

I wrote my program like this:

float valor;

scanf("%f", &valor);
printf("valor = %f\n", valor);

Once compiled, I typed 573.93 to test, and what returned was:

valor = 573.929993

I tried to use the function round() library Math. h,but it didn’t work either. I used it like this:

float valor;

scanf("%f", &valor);

printf("1° valor = %f\n", valor);//TESTE
valor = round(valor*100.0)/100.0;
printf("2° valor = %f\n", valor);//TESTE

And this returned:

1° valor = 573.929993
2° valor = 573.929993

Also used so:

float valor;

scanf("%f", &valor);

printf("1° valor = %f\n", valor);//TESTE
valor = valor * 10.0;
printf("2° valor = %f\n", valor);//TESTE
valor = valor * 10.0;
printf("3° valor = %f\n", valor);//TESTE
valor = round(valor);
printf("4° valor = %f\n", valor);//TESTE
valor = valor/100.0;
printf("5° valor = %f\n", valor);//TESTE

And what returned was:

1° valor = 573.929993
2° valor = 5739.299805
3° valor = 57393.000000
4° valor = 57393.000000
5° valor = 573.929993

Can someone help me round up the float for value = 573.93?