128 topics
How Things Work
128 how things work topics written in plain English for K-5 readers, with facts you can trace to a source.
- AI Grades 4-5 · 1156 words · simpler version
- Aircraft Grades 2-3 · 214 words
- Airplane Grades 3-4 · 548 words
- Airplane Wing Grades 4-5 · 841 words · simpler version
- Anchor Grades 3-4 · 1119 words
- Antenna Grades 2-3 · 234 words
- Archaeologist Grades 4-5 · 1162 words · simpler version
- Audio Speakers Grades 4-5 · 461 words · simpler version
- Ballpoint Pen Grades 3-4 · 415 words · simpler version
- Barista Grades 4-5 · 195 words
- Binary Numbers Grades 3-4 · 1567 words · simpler version
- Bioinformatics Grades 4-5 · 364 words
- Blacksmith Grades 3-4 · 1448 words · simpler version
- Bluetooth Grades 2-3 · 456 words
- Brass Grades 3-4 · 281 words · simpler version
- Bread Grades 3-4 · 480 words · simpler version
- Brig Grades 3-4 · 817 words
- Bus Grades 3-4 · 395 words · simpler version
- Byte Grades 4-5 · 586 words
- Camera Grades 3-4 · 422 words · simpler version
- Car Engine Grades 4-5 · 1490 words · simpler version
- Ceramic Grades 4-5 · 2229 words · simpler version
- Ceramic Tiles Grades 4-5 · 882 words · simpler version
- Ceramic Wares Grades 4-5 · 1073 words · simpler version
- Chocolate Grades 3-4 · 1121 words · simpler version
- Comic Books Grades 4-5 · 345 words · simpler version
- Compiler Grades 4-5 · 829 words
- Computer Grades 4-5 · 3215 words · simpler version
- Cryptography Grades 3-4 · 670 words
- Data Center Grades 4-5 · 146 words · simpler version
- Dice Grades 3-4 · 232 words · simpler version
- DVD Grades 3-4 · 776 words · simpler version
- Electricity Grades 3-4 · 1941 words · simpler version
- Elevator Grades 4-5 · 3344 words · simpler version
- Engine Grades 3-4 · 648 words
- Ethernet Grades 3-4 · 494 words
- Filter Grades 2-3 · 380 words
- Firefighter Grades 3-4 · 527 words · simpler version
- Firmware Grades 4-5 · 489 words
- Fluorescent Lamp Grades 4-5 · 597 words · simpler version
- Flush Toilet Grades 2-3 · 460 words · simpler version
- GUI (Graphical User Interface) Grades 4-5 · 1022 words · simpler version
- Gunboat Grades 4-5 · 729 words
- Hard Drive Grades 4-5 · 1220 words · simpler version
- Helicopter Grades 4-5 · 345 words
- History Grades 4-5 · 704 words · simpler version
- Hot Dog Grades 4-5 · 539 words · simpler version
- Hydraulic System Grades 3-4 · 262 words · simpler version
- Ice Skates Grades 4-5 · 50 words · simpler version
- Inclined Plane Grades 4-5 · 297 words · simpler version
- Infrastructure Grades 4-5 · 119 words · simpler version
- Internet Grades 4-5 · 983 words · simpler version
- Laser Grades 4-5 · 881 words · simpler version
- Lateen Grades 3-4 · 530 words
- LCD Display Grades 4-5 · 622 words · simpler version
- Lego Grades 3-4 · 458 words · simpler version
- Lever Grades 3-4 · 291 words · simpler version
- Light Bulb Grades 4-5 · 914 words · simpler version
- Longship Grades 3-4 · 1036 words
- Loudspeaker Grades 4-5 · 273 words
- M&M Candy Grades 3-4 · 291 words · simpler version
- Metal detector Grades 4-5 · 196 words · simpler version
- Microwave oven Grades 4-5 · 493 words · simpler version
- Mobile Phone Grades 3-4 · 1278 words · simpler version
- Modem Grades 3-4 · 339 words
- Modes of transport Grades 3-4 · 286 words · simpler version
- MP3 Grades 4-5 · 892 words
- Nails Grades 4-5 · 138 words · simpler version
- Newspaper Grades 2-3 · 186 words · simpler version
- Nuclear Bomb Grades 3-4 · 1325 words · simpler version
- Nurse Grades 3-4 · 566 words
- Outline Grades 3-4 · 355 words · simpler version
- Paint Grades 2-3 · 759 words · simpler version
- Paper Grades 2-3 · 942 words · simpler version
- Password Grades 3-4 · 388 words
- Pencil Grades 4-5 · 1258 words · simpler version
- Police officer Grades 4-5 · 471 words
- Porcelain Grades 4-5 · 623 words · simpler version
- Pulley Grades 3-4 · 246 words · simpler version
- Radio Grades 3-4 · 604 words · simpler version
- Radio receiver Grades 4-5 · 666 words · simpler version
- Refrigerator Grades 2-3 · 463 words · simpler version
- Rigging Grades 2-3 · 289 words
- Robot Grades 3-4 · 927 words
- Rocket Grades 2-3 · 320 words · simpler version
- Router Grades 4-5 · 418 words
- Rubber Grades 3-4 · 502 words · simpler version
- Rubber band Grades 2-3 · 44 words · simpler version
- Rubik's Cube Grades 3-4 · 510 words · simpler version
- Rudder Grades 4-5 · 198 words
- Scissors Grades 3-4 · 106 words · simpler version
- Screw Grades 2-3 · 278 words · simpler version
- Sewing Machines Grades 4-5 · 2358 words · simpler version
- Shampoo Grades 2-3 · 101 words · simpler version
- Ship Grades 3-4 · 942 words
- Society Grades 4-5 · 175 words · simpler version
- Software Grades 4-5 · 395 words
- Solar panel Grades 4-5 · 598 words · simpler version
- Subway Grades 4-5 · 138 words
- Supercomputer Grades 4-5 · 345 words
- Telephone Grades 2-3 · 413 words
- Telescope Grades 3-4 · 444 words · simpler version
- Television Grades 2-3 · 373 words · simpler version
- The Six Simple Machines Grades 3-4 · 302 words · simpler version
- Thermostat Grades 4-5 · 217 words
- Time Grades 4-5 · 398 words · simpler version
- Timeline Grades 2-3 · 176 words · simpler version
- Tire Grades 3-4 · 892 words · simpler version
- Toaster Grades 2-3 · 44 words · simpler version
- Toilet Paper Grades 3-4 · 232 words · simpler version
- Train Grades 4-5 · 1217 words
- Tram Grades 4-5 · 504 words · simpler version
- Transistor Grades 4-5 · 618 words · simpler version
- Turbocharger Grades 2-3 · 1599 words
- Unicode Grades 4-5 · 833 words
- USB Grades 3-4 · 2431 words
- Vacuum Cleaner Grades 4-5 · 169 words · simpler version
- Variable Grades 3-4 · 605 words
- Vehicles Grades 2-3 · 231 words · simpler version
- Video Game Grades 4-5 · 1057 words · simpler version
- Warship Grades 2-3 · 444 words
- Washing Machine Grades 4-5 · 566 words · simpler version
- Watermill Grades 4-5 · 755 words
- Wedge Grades 4-5 · 79 words · simpler version
- Wheel Grades 3-4 · 240 words · simpler version
- Wi-Fi Grades 2-3 · 233 words
- Workstation Grades 4-5 · 303 words
- Yahoo! Grades 2-3 · 176 words
Articles in Learn are adapted from Simple English Wikipedia and Wikijunior by their contributors, and are published under CC BY-SA 4.0. Each article names its source and links to it. See credits.