Solve: Finding the Missing Number in 0.31 - _ = 0.2

To solve this problem, we'll follow these steps:

• Subtract the given number from 0.31 to find the missing portion.
• Ensure accurate decimal subtraction.

Let's perform the calculation:
The given equation is $0.31 - x = 0.2$.
We want to find $x$. Rearranging gives us $x = 0.31 - 0.2$.
Perform the subtraction:

$0.31 - 0.2 = 0.11$

The correct answer is $x = 0.11$.

Therefore, the solution to the problem is $0.11$.