Bill is buying cans of soup. Cans come in $2$ shapes. Can $A$ is a rectangular prism shaped can with dimensions $20\times16\times10$, and can $B$ is a cylinder shaped can with radius $10$ and height $10$. Let $\alpha$ be the volume of the larger can, and $\beta$ be the volume of the smaller can. What is $\alpha-\beta$?
1. **Calculate the volume of the rectangular prism (Can A):**
   The volume \( V \) of a rectangular prism is given by the formula:
   \[
   V = \text{length} \times \text{width} \times \text{height}
   \]
   For Can A, the dimensions are \( 20 \times 16 \times 10 \):
   \[
   V_A = 20 \times 16 \times 10 = 3200 \, \text{cubic units}
   \]

2. **Calculate the volume of the cylinder (Can B):**
   The volume \( V \) of a cylinder is given by the formula:
   \[
   V = \pi r^2 h
   \]
   For Can B, the radius \( r \) is \( 10 \) and the height \( h \) is \( 10 \):
   \[
   V_B = \pi \times 10^2 \times 10 = 1000\pi \, \text{cubic units}
   \]

3. **Determine which can has the larger volume:**
   - The volume of Can A (rectangular prism) is \( 3200 \, \text{cubic units} \).
   - The volume of Can B (cylinder) is \( 1000\pi \, \text{cubic units} \).

   Since \(\pi \approx 3.14159\), we can approximate the volume of Can B:
   \[
   1000\pi \approx 1000 \times 3.14159 = 3141.59 \, \text{cubic units}
   \]

   Comparing the two volumes:
   \[
   3200 > 3141.59
   \]
   Therefore, \(\alpha = 3200\) and \(\beta = 1000\pi\).

4. **Calculate \(\alpha - \beta\):**
   \[
   \alpha - \beta = 3200 - 1000\pi
   \]

   Using the approximation \(\pi \approx 3.14159\):
   \[
   \alpha - \beta \approx 3200 - 3141.59 = 58.41
   \]

The final answer is \(\boxed{3200 - 1000\pi \approx 58.41}\)