Digital Literacy
Microsoft Office and productivity software
Office basics show up regularly on the CT.
- Word — word processor. Files end in
.docx(modern) or.doc(legacy). - Excel — spreadsheet. Files end in
.xlsx/.xls. Used for data, calculations, and charts. - PowerPoint — presentations. Files end in
.pptx/.ppt. - Outlook — email and calendar.
- OneDrive / SharePoint — cloud file storage and collaboration.
Excel cell references and formulas:
- A spreadsheet is a grid of rows (numbered) and columns (lettered). A cell is one intersection (e.g., B7).
- Formulas start with =. Examples: =A1+B1, =A1*2, =A1/B1.
- Relative reference — A1. When copied to another cell, the reference shifts.
- Absolute reference — $A$1. When copied, the reference stays fixed. $A1 locks the column; A$1 locks the row.
- Range — A1:A10 means "cells A1 through A10".
Common Excel functions:
| Function | What it does |
|---|---|
=SUM(A1:A10) |
Add the values in the range |
=AVERAGE(A1:A10) |
Arithmetic mean |
=MIN(A1:A10) / =MAX(A1:A10) |
Smallest / largest |
=COUNT(A1:A10) |
Count cells containing numbers |
=IF(A1>10, "big", "small") |
Conditional |
=VLOOKUP(value, range, col) |
Look up a value in a table |
=CONCAT(A1, B1) |
Join text |
=ROUND(A1, 2) |
Round to 2 decimal places |
Useful keyboard shortcuts:
| Shortcut | Action |
|---|---|
Ctrl + C / Ctrl + V / Ctrl + X |
Copy / paste / cut |
Ctrl + Z / Ctrl + Y |
Undo / redo |
Ctrl + S |
Save |
Ctrl + P |
|
Ctrl + F |
Find |
Ctrl + A |
Select all |
Alt + Tab |
Switch windows |
Ctrl + Alt + Del |
Security / task manager screen (Windows) |
File types
| Extension | Type |
|---|---|
.txt |
Plain text |
.pdf |
Portable Document Format |
.docx / .xlsx / .pptx |
Word / Excel / PowerPoint |
.csv |
Comma-separated values |
.jpg / .png / .gif |
Raster images |
.mp3 / .wav |
Audio |
.mp4 / .mov |
Video |
.zip / .tar.gz |
Compressed archive |
.exe / .msi |
Windows executable / installer |
.iso |
Disk image |
Web and units
- URL structure:
https://example.com/path?key=value— scheme, host, path, query. - HTTP status codes:
200OK,301moved,403forbidden,404not found,500server error. - Cookies — small files a site stores in your browser to remember you.
- Cloud service models: IaaS (rent virtual machines), PaaS (rent a managed app environment), SaaS (use software over the internet, e.g., Gmail).
Data units. 1 byte = 8 bits. 1 KB ≈ 1,000 bytes. 1 MB ≈ 1,000 KB. 1 GB ≈ 1,000 MB. 1 TB ≈ 1,000 GB.
Safe online behavior
- Hover over links before clicking; look at the real URL.
- Urgency and threats ("act now") are phishing red flags.
- Verify unexpected attachments out-of-band (phone the sender).
- Lock devices when leaving them.
- On public Wi-Fi, use HTTPS or a VPN.