<h2>Explanation:</h2>
A cube is a prism whose sides all have the same length. You can think of a cube like the three dimensional version of a square. In this problem, we know that Mary is using a microscope in order to look at a salt crystal and discovers it is shaped like a cube. Each square face has side length:
This diagram is shown in the first figure below. A crystal's square face is one of the six faces of the cube. So in order to draw it we need to know how many units we'll have in each side. Since we know that 1 unit on the grid represents 0.01mm, then:
So we will have 10 units that measure 0.01mm in each side. This is shown in the second figure below.