#include <stdio.h>

// k&r farenheit to celcius table

int main()
{
    int fahr, celsius;
    int lower, upper, step;

    lower = 0;
    upper = 300;
    step = 20;

    fahr = lower;
    while (fahr <= upper) {
        celsius = 5 * (fahr - 32) / 9;
        printf("%d\t%d\t\n", fahr, celsius);
        fahr = fahr + step;
    }

    return 0;
}

#include <stdio.h>

// k&r farenheit to celcius table

int main()
{
    float fahr, celsius;
    int lower, upper, step;

    lower = 0;
    upper = 300;
    step = 20;

    // first print table header
    printf("%s  %s\n", "Fahr", "Cels");

    // then calculate values and print them to table
    fahr = lower;
    while (fahr <= upper) {
        celsius = (5.0 / 9.0) * (fahr - 32);
        printf("%3.0f %6.1f\n", fahr, celsius);
        fahr = fahr + step;
    }

    return 0;
}

Use floats instead of ints, print table header
Use floats instead of ints, print table header
