# Bag of Wonder: The Gas Station > Fill up the car, look inside the pump, and find the giant tanks under the ground. Click! Full! A free interactive 3D exhibit for children aged 2 to 6, from Curiosity's Child in Troy, Michigan. - Interactive exhibit: https://bagofwonder.com/look-inside/gas-station/ - Ages: 2 to 6. The story is pitched at the youngest; the tap cards give older children more to chew on. - Cost: free, with no sign-in, no ads and no tracking. - Works on: phones, tablets and computers, in a web browser. Sound on for the narration. ## What it is Fill up a family car: inside the pump, the nozzle's click, the tanks underground, the tanker truck and the engine's pistons. Free, narrated 3D, ages 2 to 6. How to play: press play to hear the story (read aloud in Kelly's voice, with the words on screen). Slide the time slider back and forth to see any part again. Slide "Pull apart" to see what is hidden inside. Tap any glowing button for a fact. ## The story 1. Good morning, poppets! This is a gas station. Cars come here to fill up with gas, the fuel that makes their engines go. 2. Here comes a family car. It drives in slowly and stops right beside the pump. The driver turns the engine off. 3. The grown-up opens the little fuel door and puts the nozzle in. The children stay in their seats, buckled up and safe. 4. Let's look inside the pump! Gas comes up a pipe from under the ground. Little wheels in the meter count it, and the numbers go up and up. 5. Glug, glug, the car's tank is filling up. When the gas reaches the tip of the nozzle... click! It stops all by itself. Full! 6. Where does the gas go? A long, thin pipe carries it from the tank, under the car, all the way to the engine at the front. 7. In the engine, tiny bursts of gas go pop, pop, pop! They push the pistons up and down, and that turns the wheels. Off we go! 8. Where does the gas station keep its gas? Under the ground! Big, strong tanks hold lots and lots of gas, and pipes carry it up to the pumps. 9. Here comes the tanker truck! Its big round tank is full of gas. A hose carries the gas down into the tanks under the ground, to fill them up again. 10. The sun goes down, and the gas station lights glow, ready for the next car. Night night, gas station! ## The parts, and what we tell children These are the tap cards, word for word. - **Gas pump**: The gas pump sends gas into the car, and measures how much goes in. Only grown-ups use it. - **Screen**: The screen shows how much gas has gone into the car, and how much it costs. The numbers count up as the gas flows. - **Meter**: Inside the pump, little wheels turn as the gas flows past them. They count every drop, and tell the screen what to show. - **Pump motor**: A motor makes the gas flow, up from the big tanks under the ground and out through the hose. - **Pipe**: A strong pipe comes up from the tanks under the ground, into the bottom of the pump. - **Hose**: A strong, bendy hose carries the gas from the pump to the nozzle. - **Nozzle**: The nozzle goes into the car's fuel door. When the tank is full, gas covers a tiny hole at its tip, and click! It stops all by itself. - **The grown-up**: Filling up is a grown-up's job. Children stay buckled in the car, or hold a grown-up's hand on the sidewalk. - **Fuel door**: A little door on the side of the car. Behind it is a cap, and behind the cap, a pipe down to the gas tank. - **Gas tank**: The gas tank keeps the car's gas, under the back seat. A full tank lasts for lots of trips. - **Fuel line**: A long, thin pipe under the car carries the gas from the tank all the way to the engine. - **Engine**: The engine turns gas into turning. Tiny bursts of gas push its pistons, and the pistons turn the wheels. - **Pistons**: Pistons are like round plungers. A burst of gas pushes each one down, and up it comes again, very fast, again and again. - **Crankshaft**: A bendy shaft at the bottom of the engine. The pistons push it round and round, like legs pedaling a bike. - **Exhaust pipe**: The used-up air and gas leave the engine through the exhaust pipe, at the back of the car. - **Wheels**: Gears carry the engine's turning to the wheels, and round they go. - **The car**: This family car runs on gas. Our other car, The Car, is electric: it has a big battery instead of a gas tank. - **Underground tanks**: Big, strong tanks under the ground keep the gas safe. Each one holds enough gas for hundreds of cars. - **Tanker truck**: A tanker truck carries gas to the gas stations. Its big round tank is very strong, and it has room for lots of gas. - **Fill pipe**: The tanker's hose fits snugly onto a pipe in the ground, and the gas flows down into the tank below. ## Getting the science right What we checked, and the myths we steer around: - The car is a generic gas (gasoline) family sedan with no brand on it; its tank is under the back seat, in front of the back axle, as on most cars, and the fuel door is on the side near the back. The fuel tank, filler pipe, fuel line, the inside of the pump and the flowing gas are drawn in code; the car, the engine, the pump and the tanker are real 3D models with every brand removed. - The pump: a modern US dispenser. Gas comes up from the tanks under the ground; in most US stations the motor that pushes it is a submersible pump down in the tank, and some pumps have their own motor inside instead. The page shows a motor inside the pump (as in Kelly's painting) and the tap card says only that "a motor makes the gas flow, up from the big tanks under the ground", which is true either way. - The meter: the page shows gear-like wheels turning as the gas flows (like the positive-displacement meters in many pumps). A pulser counts their turns and the screen shows gallons and dollars; the price on the screen is made up. - The nozzle click is real physics: a small tube at the tip of the nozzle lets air in while the tank fills; when gas covers the tip, the air is cut off, the pressure drops and a valve snaps shut. The page says "gas covers a tiny hole at its tip, and click! It stops all by itself." - Underground tanks: real station tanks are double-walled steel or fiberglass, usually 10,000 to 20,000 gallons each, buried a few feet under the concrete. "Enough gas for hundreds of cars" is fair: a car takes about 10 to 15 gallons. The amber "gas" inside the painted tanks is a see-through view, not what the tanks look like. - The tanker truck carries gas from a terminal to the station and drops it through a fill pipe into the underground tank, by gravity, through a hose. The truck on the page is a tractor and tanker trailer; its orange hazard plates (UN 1203, gasoline) are the real safety markings and are kept. - The engine: a real four-cylinder engine model with a see-through block. The crankshaft turns, each piston slides in its cylinder and each rod swings between them, following the model's own measurements; the little bursts at the top fire in a real four-cylinder order (1-3-4-2), once every two turns per cylinder. Real bursts come from gas mixed with air and lit by a spark plug; the page says "tiny bursts of gas" and does not show flames or say "burn" or "explode". - Gas and electric: the Car exhibit's car is electric (a battery and a motor); this one is a gas car. The tap card on the car says so. - Safety: only grown-ups use the pump; the children stay buckled in the car (or hold a grown-up's hand on the sidewalk). The page never invites a child to touch a pump, a nozzle or gas, and never says gas is food or a drink: it is "the fuel that makes their engines go". - Gentle wording: no spills, no fire, no smells described; the car drives in and away "slowly"; the tanker is "very strong". ## How to use it with children Watch the story with the sound on. At the pump, pause on "Inside the pump" and trace the path with a finger: up the pipe, through the motor, round the meter's wheels, out of the hose. At the engine, count the pistons together and watch which one goes pop. Then compare with The Car: where does each car keep its energy? Ask more than you tell, and let the child drive. Then step away from the screen: next time you fill up, let the child watch the numbers count up from the back seat, buckled in, and listen for the click. Make a "meter" with two cotton reels on pencils joined by a rubber band: turn one and watch the other turn. At home, play gas station with a toy car and a jump rope for a hose (no real fuel, ever). A few minutes together is plenty. The exhibit is a doorway to the real thing, not a replacement for it. ## Credits and licenses The real scans, maps and photographs belong to their makers, under the licenses below. The words, story and code are Curiosity's Child's. - The car: [a generic sedan by mmcworks](https://sketchfab.com/3d-models/generic-sedan-car-58c33766470d46e7b2aed542650494e5) (CC BY), painted sky blue, with nothing on its badge - Its engine: [a see-through four-cylinder engine by rafaelaraujo55](https://sketchfab.com/3d-models/inline-4-engine-64c16a336bd74b2db337ca03bc156f7a) (CC BY) - The pump: [a modern gas pump by AsrorZ](https://sketchfab.com/models/b0b667ff64324f6b92974386266c10f2) (CC BY), with every name, logo and advert taken off and repainted - The tanker truck: [a fuel truck by simonthedigger](https://sketchfab.com/3d-models/fuel-truck-443da3cd0f4547c980e52168bfbe7b76) (CC BY), its company colors taken off - The grown-up: [Nathan, a real 3D-scanned person, by Renderpeople](https://sketchfab.com/3d-models/nathan-animated-003-walking-3d-man-143a2b1ea5eb4385ae90a73657aca3bc) (CC BY) - The gas station in the morning and the evening, and the tanks under the ground: watercolor paintings Kelly made with Grok - The light on the car: a real 360° photograph from [Poly Haven](https://polyhaven.com) (CC0) - The inside of the pump (after Kelly's painting), the gas tank, the fuel pipes, the hoses and the flowing gas are made in code - Real sounds from Freesound ([CC0](https://creativecommons.org/publicdomain/zero/1.0/), thank you!): [a quiet street with birds](https://freesound.org/s/135074/) (mzui), [a car arriving and parking](https://freesound.org/s/508901/) (ahriik), [filling up a car, and the nozzle's click](https://freesound.org/s/382268/) (XiiiSamples), [a car engine ticking over](https://freesound.org/s/369053/) (AndrewAlexander), [a diesel truck idling](https://freesound.org/s/128160/) (ibirdfilm), [a summer evening with crickets](https://freesound.org/s/746366/) (RyanKingArt) - Music-box tune made for this page ## More on the Things That Go shelf - [The Car](https://bagofwonder.com/look-inside/car/index.md): A family car’s whole day: buckle up, drive the lanes, swish through the rain. Then pull it apart! - [The Excavator](https://bagofwonder.com/look-inside/excavator/index.md): Dig, scoop and pour! Meet the driver, fill the dump truck, then pull the digger apart. ## About Bag of Wonder A free library of interactive 3D "look inside" science exhibits, made at Curiosity's Child, a licensed home daycare in Troy, Michigan. Secular and science-based; welcoming to all. - All exhibits and how we make them: https://bagofwonder.com/llms.txt - For grown-ups and AI assistants: https://bagofwonder.com/look-inside/about/ - To cite: "The Gas Station", Bag of Wonder, Curiosity's Child (Troy, Michigan). https://bagofwonder.com/look-inside/gas-station/