Every day we complete a wide variety of actions—from brushing our teeth to walking up stairs to eating lunch. Each action involves a series of steps. The steps are taken in a very specific order, or sequence. For example, in the morning, as we brush our teeth, we must first remove the cap of the toothpaste, then put the toothpaste on the toothbrush, and then brush our teeth. If the order of these steps were changed, the action would be very different. Can you imagine if you tried to put toothpaste on a toothbrush without first removing the cap?  You would certainly have a hard time brushing your teeth. 

When instructing someone or something to complete a task, it's not only the sequence of steps that's important. The key to communicating the task correctly also lies in using exact vocabulary when describing each step in the process. For example, the robot in the Cyberchase segment can only recognize the commands "Walk", "Walk #", "Turn right", "Turn left", "Extend Arm", and "Retract Arm." The CyberSquad must figure out how to translate their directions using the series of commands that the robot understands.

Let's take driving directions, for example. Suppose an athletic coach must provide parents with directions to a game in another town and says, "Drive down Washington Street, take a left, drive three blocks, and turn at the library. Go straight until you see the field." Do you think all the players would find the field? The vocabulary of the commands is understandable, but a driver may wonder "How far must I drive on Washington Street before I take a left? On which street do I make the left? Do I make a left or a right at the library? And how far do I drive after I make the turn? The initial directions were not specific, so it is possible that some of the players will not find the field. As you see, when you are providing instructions to others, it is important to be able to communicate precisely.  

To extend this idea to mathematical computation, consider the steps taken to evaluate numerical expressions. The order of operations is an important mathematical convention that must be applied to every problem. For example, in evaluating the expression 3 + 5 * 4, if you were to first perform the addition, you would get 8 * 4, or 32. However, the order of operations dictates that multiplication must be completed before addition, which gives the result 3 + 20, or 23. Because of this mathematical convention, the order of steps is very important and if the order of operations is not applied correctly, an incorrect answer will result.

To learn more about the design process, check out Design for Function QuickTime Video, What Is the Design Process? QuickTime Video, and Testing with Models QuickTime Video.

To learn about kid designers, check out Kid Designer: A Comfortable Cardboard Chair QuickTime Video.

To learn more about kids using engineering design principles, check out Automatic Door Opener QuickTime Video and LEGO® Robots QuickTime Video.

Print Background Essay