Returns the least common multiple of integers. The least common multiple is the smallest positive integer that is a multiple of all integer arguments number1, number2, and so on. Use LCM to add fractions with different denominators.
If this function is not available, and returns the #NAME? error, install and load the Analysis ToolPak addin.
How?
 On the Tools menu, click AddIns.
 In the AddIns available list, select the Analysis ToolPak box, and then click OK.
 If necessary, follow the instructions in the setup program.
Syntax
LCM(number1,number2, ...)
Number1, number2,... are 1 to 29 values for which you want the least common multiple. If value is not an integer, it is truncated.
Remarks
 If any argument is nonnumeric, LCM returns the #VALUE! error value.
 If any argument is less than zero, LCM returns the #NUM! error value.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

A 
B 
Formula 
Description (Result) 
=LCM(5, 2) 
Least common multiple of 5 and 2 (10) 
=LCM(24, 36) 
Least common multiple of 24 and 36 (72) 
