Solve Using Area Models: Finding 1.5 - 0.8 with Grid Representations

To solve this problem, start by re-evaluating the appearance of this problem statement:

• This visually seems to indicate finding a valid operation setup with the choice alternatives.

Since the intention is seeming to lead to an operation like:

• Identify that two blocks represent this subtraction problem, further confirming with operation balance $0.15 - 0.8$.
• Translate this problematically as trying different $x$ ensuring subtraction $x - 0.8$, achieves a valid metric.
• Among choices look into possible well-matching 0.7

Breaking down and confirming,

• $0.7 - 0.8 = 0$: Provides true balance operational correctness reaching through rest items.

Therefore, the correct answer for the problem based on range and method assessment is $0.7$, also the third choice.