35 topics · Preschool to Grade 8

How computers and the internet work

How does a message cross the internet in a blink, and how does a touchscreen know where you tapped? These topics explain the technology children use every day. They see how computers store and process information, how Wi-Fi, Bluetooth and cell towers carry signals, how GPS finds a position and how search engines sort billions of pages. Safety topics show why strong passwords, two-step verification and encryption protect accounts, and how spam filters catch junk mail. Other topics open up cameras, printers, robots, video games, speech recognition and chatbots. Each one has an animation, a look inside, a simulation to try and a challenge, written for preschool, elementary and middle school.

1Watch it
2Look inside
3Try it
4Solve a challenge
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35 topics in Computers & communication

Computers & communication

#49 Computers & communication How does a camera take a picture? Follow light through a lens to a sensor. Adjust focus and lighting, capture an image, and zoom in to discover its pixels.

#50 Computers & communication How does a touchscreen know where you touched? Tap a transparent screen and watch a simplified sensor grid detect the location. Follow that information into a button press, swipe, or drawing.

#51 Computers & communication How does the internet send a message? Break a message into packets, route them through a network, and reassemble them. Help packets find another route around a broken connection.

#52 Computers & communication How do robots work? Give a robot sensors, motors, and instructions. Help it navigate a maze, avoid obstacles, or sort objects, then improve its behavior.

#53 Computers & communication How do video games work? Explore input, game rules, animation, collision detection, and scoring. Change gravity or movement speed in a tiny game and play the result.

#54 Computers & communication How does a computer follow instructions? Explore the processor, memory, storage, and input/output devices. Follow a simple instruction through the system and build a short sequence of commands.

#55 Computers & communication How does Wi-Fi connect devices? Send simplified radio messages between a device and router. Move devices around a virtual home and investigate how distance and walls affect the connection.

#56 Computers & communication How does GPS know where you are? Compare signals from several satellites and watch a receiver calculate its position. Explore how signal timing helps locate a moving character.

#57 Computers & communication How does a printer make colorful pictures? Look inside an inkjet printer and build a picture from tiny cyan, magenta, yellow, and black dots. Switch colors on and off to compare results.

#58 Computers & communication How do microphones and speakers work? Watch sound vibrations become an electrical signal and turn back into vibrations. Compare quiet, loud, low-pitched, and high-pitched sounds.

#326 Computers & communication How do QR codes store information? Encode a short message into a square pattern and decode it onscreen.

#327 Computers & communication How does a search engine find websites? Build a miniature index and compare which pages match different searches.

#328 Computers & communication How do passwords protect accounts? Explore how a system checks fictional passwords without displaying stored secrets.

#329 Computers & communication How does two-step verification protect accounts? Unlock a pretend account using two proofs and explore their separate roles.

#330 Computers & communication How does encryption keep messages private? Scramble a message in a simple model and restore it using the appropriate key.

#331 Computers & communication How does a video call work? Follow pictures and sound through encoding, transmission, and playback between virtual devices.

#332 Computers & communication How does streaming video reach a screen? Fill a playback buffer and explore what happens when incoming data slows.

#333 Computers & communication How does cloud storage keep files available? Save a drawing remotely and retrieve it from different virtual devices.

#334 Computers & communication How do backups recover lost files? Save copies, change a pretend folder, and restore an earlier version.

#335 Computers & communication How does file compression make files smaller? Replace repeated patterns with shorter descriptions and compare file sizes.

#336 Computers & communication How does animation turn pictures into movement? Arrange frames, change playback speed, and create a short animated scene.

#337 Computers & communication How does a screen reader describe a webpage? Navigate spoken headings, links, and image descriptions on a sample page.

#338 Computers & communication How does speech recognition turn sound into words? Follow a simplified journey from sound patterns to written text.

#339 Computers & communication How does a translation app change languages? Translate sample sentences and explore how context affects meaning.

#340 Computers & communication How does image recognition identify objects? Label pictures, test a simple classifier, and investigate its mistakes.

#341 Computers & communication How does a chatbot create replies? Explore a simplified word-prediction model and compare outputs for different questions.

#342 Computers & communication How do map apps choose routes? Compare routes using distance, closures, and travel time on a model network.

#343 Computers & communication How does Bluetooth connect nearby devices? Pair virtual gadgets and investigate communication as they move farther apart.

#344 Computers & communication How do walkie-talkies let people talk? Select matching channels and follow voice signals between transmitters and receivers.

#345 Computers & communication How do undersea cables carry information? Trace light signals through a cutaway cable connecting distant coastlines.

#346 Computers & communication How do phone towers pass along a moving call? Move a phone between coverage areas and watch its connection transfer.

#347 Computers & communication How do spam filters recognize unwanted messages? Sort fictional messages using clues and compare correct detections with mistakes.

#348 Computers & communication How do computers store letters and emojis? Match characters to numerical codes and turn stored codes back into symbols.

#349 Computers & communication How can messages survive small transmission errors? Damage an encoded message and use extra information to detect or repair errors.

#350 Computers & communication How do computers sort large lists? Try different sorting strategies and compare the number of steps required.

Keep exploring

Games to play

Robot RoutesSnap together arrow, repeat and dance blocks to guide Bolt the robot home.
Bug DetectiveA robot program almost works. Run it, spot the buggy block, and fix it.
Safe Message DetectiveRead made-up messages, pop-ups and posts, spot the clues, and choose the safe, kind thing to do.

Guide for grown-ups

How to start homeschooling: a step-by-step guide for familiesA guide for parents · 7 min read