The expression "2 + 4 + 6 + 8" represents a simple addition problem involving four even numbers. Each number is an integer that is divisible by 2, starting from 2 and increasing by 2 each time. This sequence is part of the set of even numbers, which are commonly used in various mathematical operations. When you add these numbers together, the total is 20. This can be calculated step by step: first, add 2 and 4 to get 6, then add 6 and 6 to get 12, and finally add 12 and 8 to reach 20. This process illustrates basic arithmetic skills often taught in early mathematics education.