Have you ever made a mistake when trying to solve a math problem? It can be pretty easy to
do, and often will result in losing points on an exam. In the real world, such mistakes can
have more serious effects: Miscalculating how much gas you have left in your car will leave
you stranded. Miscalculating how much money you have left in your bank account might cost
you an overdraft fee. Even more serious, miscalculations have resulted in serious accidents
happening many times. Once, as a result of not using the correct units, a satellite sent to
Mars burned up in the atmosphere, wasting over $300 million dollars.
Fortunately, there are steps you can take to avoid making errors along the way. One of
these strategies is manipulating formulas so they are solving for the variable you want before
you substitute values for the variables in the formula. This technique is especially useful
when working with large, unwieldy numbers.