1. The problem states: 1/8 of a number is 9, and we need to find the whole number. 2. Let the whole number be $x$. 3. The equation based on the problem is: $$\frac{1}{8}x = 9$$ 4. To find $x$, multiply both sides of the equation by 8 to cancel the fraction: $$8 \times \frac{1}{8}x = 8 \times 9$$ 5. Using the cancellation rule, we get: $$\cancel{8} \times \frac{1}{\cancel{8}} x = 72$$ 6. Simplifying, we have: $$x = 72$$ 7. Therefore, the whole number is 72.