Counting Units in 7 Squares: Visual Measurement Problem

To solve this problem, we will count the number of squares presented in the image. The image displays a series of identical squares arranged in a row.

Let's go through the steps:

• Observe the number of squares shown in the diagram.
• Starting from the leftmost side, count each square until we reach the rightmost side.

Upon counting each square one by one, we observe:

1. The first square (1st unit).
2. The second square (2nd unit).
3. The third square (3rd unit).
4. The fourth square (4th unit).
5. The fifth square (5th unit).
6. The sixth square (6th unit).
7. The seventh square (7th unit).

Therefore, the number of squares, or units, represented is $7$.

The correct answer, based on the choices provided, is choice $4$, which corresponds to $7$.