# Lean Excel: Top Functions

This Lean Excel series focuses on time-saving tools that will help you reduce the waste associated with data analysis. One of the tenets of lean manufacturing theory is using specialized tools to accomplish a task. You could use a wrench to drive a nail but a
hammer will get the job done much faster. Remember time is money.

Think of the built-in functions as specialized tools. Let’s say you needed to find the average of a dataset that is in A1 through A5. Remember the average is the sum of all the numbers in a dataset divided by the count of numbers in that dataset. Let’s look at three ways to find the average. First, you could use the formula =(A1+A2+A3+A4+A5)/5.
Second, you could use the SUM and COUNT functions =SUM(A1:A5)/COUNT(A1:A5).

Or lastly, you could use the AVERAGE function =AVERAGE(A1:A5). Although all three options give you the same answer, using the AVERAGE function is clearly the most efficient. But in order to use the AVERGE function, you need to know that it exists and what requirements you need to use it.