1. **State the problem:** Calculate the sum of 57894.99 and 5785. 2. **Formula used:** Addition of two numbers is given by $$a + b$$ where $a$ and $b$ are the numbers. 3. **Apply the formula:** $$57894.99 + 5785 = ?$$ 4. **Perform the addition:** $$57894.99 + 5785 = 63679.99$$ 5. **Conclusion:** The sum of 57894.99 and 5785 is 63679.99.