1. The problem is to find the sum of 2000 and 1000. 2. The formula for addition is $a + b = c$, where $a$ and $b$ are the numbers to add, and $c$ is the result. 3. Applying the formula: $2000 + 1000 = 3000$. 4. Therefore, the sum of 2000 and 1000 is 3000.