1, draw small squares on clean white paper, with the area of each small square as small as possible. 2. Choose flat leaves and put them on white paper with small squares on it. Use a pen to gently trace the outline of the leaf along its edge. 3. Take off the leaves and count the number of small squares. If the edge part is incomplete, it can be calculated with two squares or with three squares. 4. Finally, the area of a leaf can be calculated by using the relevant formula. 5. Multiply the area by the thickness to get the volume of leaves.

Area is a quantity indicating the degree of a two-dimensional figure or shape or plane layer in a plane. A surface region is a simulation on a two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness, which is necessary to form a shape model.

The area of a shape can be measured by comparing a fixed size shape with a square. In the International System of Units (SI), the standard unit area is square meters. A square area with an area of one meter and an area of three square meters will have the same shape as three such squares. In mathematics, the unit square is defined as 1, and the area of any other shape or surface is a dimensionless real number.