Problems involving the estimation of physical quantities are often referred to as a Fermi problem, named after the physicist Enrico Fermi, who is known for making quick, rough estimates based on simple calculations and assumptions. The determination of the number of blades of grass on a soccer field is an example of a Fermi problem. The answer to any Fermi problem, called the Fermi estimate, is achieved by breaking the problem into smaller parts and using the available information to roughly estimate the unknowns. Now, the number of blades of grass in a soccer field can be estimated by considering the field's dimensions and estimating that there are 20 grass blades in one square centimeter. From the length and width, the area of the soccer field is calculated. Next, converting the field's area into centimeters and multiplying the area by the number of blades of grass per unit area gives the Fermi estimate of the total number of blades of grass.