You're likely referring to a microscope's objective lenses and their magnification. Here's how it works:

* Objective Lenses: Microscopes have multiple objective lenses, each providing a different magnification. Common ones include 4x, 10x, 40x, and 100x.

* Total Magnification: The total magnification you see through the microscope is calculated by multiplying the objective lens magnification by the magnification of the eyepiece lens (usually 10x).

Example:

* If you're using a 4x objective lens, the total magnification would be 4x * 10x = 40x.

Therefore, 4x on the low power objective lens actually results in a 40x magnification, not 40x the microscope itself.

Let me know if you'd like more information about microscopes!