1. **State the problem:** Calculate the value of $9 \div 0.25$. 2. **Formula and rules:** Division of numbers can be rewritten as multiplication by the reciprocal. That is, $a \div b = a \times \frac{1}{b}$. 3. **Apply the formula:** $$9 \div 0.25 = 9 \times \frac{1}{0.25}$$ 4. **Calculate the reciprocal:** $$\frac{1}{0.25} = 4$$ 5. **Multiply:** $$9 \times 4 = 36$$ 6. **Final answer:** $$9 \div 0.25 = 36$$ This means dividing 9 by 0.25 is the same as multiplying 9 by 4, resulting in 36.