1. **State the problem:** Calculate the distance from the center of a circle to its border given a radius. 2. **Formula:** The distance from the center to the border of a circle is the radius $r$. 3. **Example:** Suppose a circle has a radius of $5$ units. 4. **Calculation:** The distance from the center to the border is simply $r = 5$ units. 5. **Explanation:** Since every point on the border is exactly $5$ units from the center, the distance is $5$. 6. **Conclusion:** The distance from the center to the border of this circle is $5$ units.