Today you will
- learn to read the letters after the dot in a filename
- match each file type to the app that opens it
- make a file-type sheet for your portfolio
Warm-up
Look at this filename: {{code:work_experience_report_final.pdf}}. What kind of file do you think it is? Would you edit it, or would you mainly read it and send it?
A file extension is the letters after the last dot in a filename. It tells the computer which app opens the file.
You can edit a .docx file. A .pdf file keeps its layout fixed, so use it for finished work.
If you open a file in the wrong app, you get nonsense or a blank window. The file is fine.
A .zip file is one package that holds several files.
Example: {{code:placement_hours.xlsx}} opens in Excel Online or Google Sheets.
Use this card for the rest of the lesson.
| Extension | Job | Open with |
|---|---|---|
| {{code:.docx}} | Draft and edit text | Word Online or Google Docs |
| {{code:.pdf}} | Finished work to read and send | Browser or PDF reader |
| {{code:.xlsx}} | Budget, tracker, tally | Excel Online or Google Sheets |
| {{code:.pptx}} | Slide deck or pitch | PowerPoint Online, Google Slides or Canva |
| {{code:.jpg}} / {{code:.png}} | Photo (jpg) or sharp logo, often with a clear background (png) | Photos, Preview, browser or image editor |
| {{code:.mp3}} / {{code:.mp4}} | Audio only (mp3) or video (mp4) | Media player |
| {{code:.zip}} | Package of several files | Extract first, then open the files inside |
We will do this one together as a class. Read the letters after the dot before you decide, because the name alone can trick you. If you get stuck, look back at the quick-reference card.
Which app opens this file?
Common snags
- I can't see the extensions. On Windows, open File Explorer, click {{menu:View}} and tick File name extensions.
- I see nonsense text or a blank window. The wrong app opened the file. Close it and open it with the right app.
- My zip file won't open like a folder. Right-click it and choose {{btn:Extract All}} first.
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