#include <stdio.h>
#include <stdlib.h>

int main()
{

    float fv;

    fv = 123.0f;

    printf ("%f\n", fv );

    fv = 123.0e1f;

    printf ("(e1): %f\n", fv );

    fv = 123.0e2f;

    printf ("(e2): %f\n", fv );

    fv = 123.0e3f;

    printf ("(e3): %f\n", fv );

    fv = 123.0e-1f;

    printf ("(e-1): %f\n", fv );

    fv = 123.0e-2f;

    printf ("(e-2): %f\n", fv );

    fv = 123.0e-3f;

    printf ("(e-3): %f\n", fv );

    return 0;
}

/*
output:

123.000000
(e1): 1230.000000
(e2): 12300.000000
(e3): 123000.000000
(e-1): 12.300000
(e-2): 1.230000
(e-3): 0.123000

*/