Solving problems involving absolute value is one of the hardest topics for students learning in elementary algebra course. This is an important topic in student's mathematics life since absolute value functions are important example of a function which is continuous on the real line but not differentiable at the origin. A deep understanding of these topics is very important for students. Some students understand the definition of absolute value but are still unable to apply the definition to solve the problems. Others do not understand this concept. This article focuses on using the number line when introducing/explaining this topic. A visual technique called box method helps students to write each step with correct reasoning when solving problems involving absolute value. The number line and box method helps them to see the connection between the concept and procedure used to solve the problems involving absolute value.