1. The problem is to multiply the matrix $\begin{bmatrix}a & b \\ c & d\end{bmatrix}$ by the scalar 1000. 2. The formula for scalar multiplication of a matrix is to multiply each element of the matrix by the scalar: $$\text{If } M = \begin{bmatrix}m_{11} & m_{12} \\ m_{21} & m_{22}\end{bmatrix}, \text{ then } kM = \begin{bmatrix}k m_{11} & k m_{12} \\ k m_{21} & k m_{22}\end{bmatrix}$$ 3. Applying this to our matrix: $$1000 \times \begin{bmatrix}a & b \\ c & d\end{bmatrix} = \begin{bmatrix}1000a & 1000b \\ 1000c & 1000d\end{bmatrix}$$ 4. This means each element is simply multiplied by 1000. 5. The final answer is: $$\boxed{\begin{bmatrix}1000a & 1000b \\ 1000c & 1000d\end{bmatrix}}$$