Fall in Love with Spreadsheets: Let the Spreadsheet Do the Math

If the word formula makes you tense up a little, you’re not alone.

For a lot of teachers, formulas feel like:

• something you’re supposed to already understand
• something that’s easy for “techy people”
• something that can break everything if you do it wrong

BUT...
You don’t need to understand formulas to benefit from them. You just need to know what they can do for you.

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What a Formula Really Is

A formula is just an instruction. It’s the spreadsheet version of saying: “Add these up.” “Find the average.” “Count how many things I have.”

You’re not doing math. You’re telling the spreadsheet to do it for you.

The Three Formulas Teachers Actually Need

We’re not doing anything fancy here. These three cover most real classroom needs.

1️⃣ SUM “Add this up”

Use this when you want totals.
Examples:

• Total points
• Total assignments
• Total tasks completed

You're basically telling the spreadsheet to: “Add everything in this column.” 

Formula: =SUM(RANGE)

Example: =SUM(A3:A15)

PLEASE NOTE: RANGE is the section of cells you want counted. Like Cell A1 through Cell A5. 

2️⃣ AVERAGE “What’s the average?”

This one does the heavy lifting for grades!

Examples:

• Quiz averages
• Assignment averages
• Overall progress checks

Meaning: “What’s the middle-ish score?”

Formula: =AVERAGE(range)
Example: =AVERAGE(A3:H3)

3️⃣ COUNT “How many things are there?”

This is surprisingly useful.

Examples:

• How many assignments were turned in
• How many tasks are left
• How many days something happened

So you're saying: “How many boxes have something in them?”

This one has a couple of different ways to do this:

Count the number of numeric vales in a dataset (how many numbers are in the cells this range?)

Formula: =COUNT(RANGE)

Example: =COUNT(A3:A16)

Count the number of values in a dataset (doesn't have to be numbers; how many names are in this range?)

Formula: =COUNTA(RANGE)

Example: =COUNTA(A3:A16)

Count if a criterion is met (like if a checkbox is checked)

Formula: =COUNTIF(RANGE, CRITERION)

Example: =COUNTIF(A3:A16, TRUE)

The Best Part: You Don’t Have to Memorize Anything

You don’t need to remember formulas or write them from scratch.

Most spreadsheets:

• suggest formulas as you type
• show you what they do in plain language
• let you undo instantly if something looks wrong (CTRL+Z is YOUR FRIEND!)

Start Small (Always)

Just like the rest of this series, the goal isn’t to overhaul everything.

Try one of these you just read about:

• Add a total at the bottom of one column
• Let the spreadsheet calculate one average
• Count how many tasks are done

That’s it. Once you see it work, your confidence grows naturally.

Want This Done For You?

I added simple average formulas to a new tab in the Teacher Life Starter Spreadsheet so you can:

• see them in action
• use them without setting anything up
• trust that the math is handled

Download the updated spreadsheet below.

UPDATED Spreadsheet - this link will force a copy

Download a Copy Here - this link will download an Excel or Apple Numbers file

Wrapping Up the Series

Over the last four weeks, you’ve learned that:

• Spreadsheets aren’t scary
• You don’t need to be techy
• You can start small and still see big benefits

You can check out the other posts in this series by clicking below: 

 Week 1: Why every teacher needs one spreadsheet

Week 2: Spreadsheets for teachers who swear they aren't "techy"

Week 3: Checkboxes, Color Coding, and the Joy of Letting the Spreadsheet Think for You