1. **State the problem:** Calculate the sum of 1, 2, and 3. 2. **Formula used:** The sum of numbers can be found by adding them directly: $$\text{Sum} = a + b + c$$ 3. **Apply the formula:** Substitute the values: $$\text{Sum} = 1 + 2 + 3$$ 4. **Calculate step-by-step:** $$1 + 2 = 3$$ $$3 + 3 = 6$$ 5. **Final answer:** $$\boxed{6}$$ The sum of 1, 2, and 3 is 6.