Expected expression error on a temperature conversion table

Expected expression error on a temperature conversion table

Getting an "expected expression error" on line 17 when following the C
programming book. Complete noob here and not sure what I'm doing wrong.
int main()
{
float fahr, celsius;
int lower, upper, step;
lower = 0; /* lower limit of temperature table */
upper = 300; /* upper limit */
step = 20; /*step size */
fahr = lower;
while (fahr <= upper ) {
celsius = (5.0/9.0) * (fahr - 32.0);
printf("%3.0f %6.1f\n", fahr, celsius);
fahr = fahr + step;
}
return 0;
}