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Once you have finished the planning phase, you should be able to create your model. Use your diagram, data, and other information to make your mathematical model. Make sure to check your notes often to ensure accuracy.  Make sure that your model represents the actual relationship among your data that you are trying to accomplish. For more advanced models, you may need to use a computer program. It is important to verify the validity of your model’s results before you try to do anything else with your model. Apply your data and see if the model is valid. Are your results what you expected? Do they make sense? Are the results repeatable?  Solve the equation V = h x w x l to determine if your results make sense. Repeat the solution to determine if your results are repeatable. In order to make your model useful for further applications, you need to consider how it could be improved. Are there any variables that you should have considered? Are there any restrictions that could be lifted? Try to find the best way to improve upon your model before you use it again.  For example, if you want to have 3 feet (0.91 m) of space to walk through your storage unit, you could adjust your equation to account for that space. Just deduct the space you will lose from the appropriate number in your equation. In this case, you could adjust your equation to read V = h x (w-3) x l  After you have identified ways to improve your model, make the changes and test it again.

Summary:
Create your model. Test your model. Determine how the model could be improved.