Making a GCF and LCM calculator in Google Sheets

Howdy everyone! It’s been a looooong time but I’m back and ready to post more frequently (at least I hope)

Today is a little tutorial for just about any middle school (probably a fifth grade too) math class. It shows you how to create a “calculator” in Google Sheets (or any spreadsheet program – looking at you Excel) of how to automatically calculate greatest common factor (GCF) and least common multiple (LCM).

It’s pretty straight forward so enjoy!

If you want a PDF of the instructions click HERE!

If you want a clean e-version click HERE!

Finding the greatest common factor and the least common multiple is not particularly hard but it is a necessary skill in math. When dealing with smaller numbers, it can be very easy and even done mentally. However, when dealing with larger numbers it can pose a real problem.

This guide will show you how to make that in Google Sheets. This guide can also be applied to Microsoft Excel, Libre Office Calc and any other decent spreadsheet program.

Step 1 – Create a new spreadsheet

In order to do this, we need to create a new spreadsheet.

Go to drive.google.com and click on the New button.

Then select Google Sheets.

This will create a new spreadsheet which looks like this.

Name your Google Sheet

It is always a good idea to name your files, so you can easily find it again.

To do this, click where it says Untitled spreadsheet.

Then type in an appropriate name. I am calling mine GCF – LCM Calculator

Step 2 – Set up your spreadsheet

Now that the spreadsheet has been created and named, it is time to set it up.

Make your spreadsheet look like mine:

Cell A1 = Number #1
Call B1 = Number #2
Cell C1 = Number #3
Cell D1 = GCF
Cell E1 = LCM

*NOTE: THOSE RECTANGLES THAT MAKE UP THE SPREADSHEET ARE CALLED CELLS*

Step 3 – Add some numbers

In this part I just added some numbers.

Use the same numbers I have so you can compare your final results with mine.

To enter the numbers, just click on the cell and type them in.

Step 4 – Calculating the GCF

We are now going to enter a formula to have the spreadsheet automatically calculate the greatest common factor for us.

Anytime we enter an equation we MUST start with an equal sign =

We will type this formula is cell D2:

=gcd(A2,B2,C2)

Here is what is happening.

We are telling the spreadsheet to find the GCF that is what this part of the formula does.

=gcd

The GCD means greatest common divisor which works for us. We need the parenthesis to help the spreadsheet what to look for and the letters and numbers refer to the cells.