<human>: What is the most important thing to remember when calculating elapsed time?
<bot>: The most important thing to remember when calculating elapsed time is to use a consistent unit of measurement. For example, if you are measuring how long it takes for an object to move from one place to another, make sure that you measure distance in the same units (such as feet or meters) throughout the experiment. Additionally, be sure to account for any variables that may affect your results, such as changes in temperature and air pressure.