1. The problem is to divide 9 by 72. 2. The division formula is $\frac{a}{b}$ where $a$ is the numerator and $b$ is the denominator. 3. Substitute the values: $\frac{9}{72}$. 4. Simplify the fraction by finding the greatest common divisor (GCD) of 9 and 72, which is 9. 5. Cancel the common factor 9: $$\frac{\cancel{9}}{\cancel{72}} = \frac{1}{8}$$ 6. So, $9 \div 72 = \frac{1}{8}$. 7. The final answer is $\frac{1}{8}$ or 0.125.