Seven investigations. Text only. No account, scripts, video, or 3D required. Use your browser’s Print → Save as PDF to keep a copy for offline study. Expand the answer panels before saving if your browser does not include them automatically.
Start with a familiar example. Try an explanation in your own words, then compare. Return on another day and try without the example. Speak, draw, write or use supported communication; spelling and speed are not the goal.
This edition is in English. You may discuss ideas in your own language. Browser translations are not reviewed translations; check important wording against the source. Some examples concern child safety and are optional—no personal disclosures are requested.
Reading · counting · evidence
The missing water
Start here
Start with 8. Count back to 5. Then separate what you counted from Mina’s explanation.
A worked example
The school garden has two covered trays. Mina puts 8 tokens beside each tray to represent water. At the next check, tray A has 5 tokens and tray B has 7. “The plant in A drank all the missing water,” she says. Her friend asks, “Could water also have evaporated?” This is a fictional investigation. Tokens represent amounts; they are not real measurements.
How many tokens were removed from tray A?
Reasoning: 8 − 5 = 3. We know the difference. The count alone cannot tell us where the water went.
Deeper explanation
An observation tells what was recorded. An explanation proposes why it happened. Compare quantities, then ask what evidence could distinguish explanations.
Try without looking
A shelf held 12 books. Now it holds 8. What do you know, and what do you not know?
Compare the reasoning after trying
Four books are no longer on the shelf. The count does not tell us who moved them or why.
Two trays lose different amounts of water. Does that prove one plant drank more?
Compare the reasoning after trying
No. Evaporation, leaks, measurement differences and plant uptake could contribute. Compare evidence before choosing an explanation.
Look for the request, the threat, and the secrecy. Choose an action that connects Jo to help.
A worked example
In this fictional story, an older person keeps asking Jo for private pictures and says, “Do not tell anyone. You will be in trouble.” Jo feels unsure. The request and threat are not Jo’s fault. Jo can tell a trusted adult. If that adult does not help, Jo can tell another. Jo does not have to investigate or prove what happened.
What should Jo understand?
Reasoning: Yes. Responsibility belongs to the person making the unsafe request. Children deserve protection and support.
Deeper explanation
Pressure, threats, unwanted contact, and requests for private pictures are reasons to seek help. A familiar or powerful person can behave unsafely. Freezing, complying, or telling later never makes abuse the child’s fault.
Try without looking
In a fictional story, an online player threatens a child who refuses to send private pictures. What could the child do?
Compare the reasoning after trying
Seek help from a trusted adult, and another if the first does not help. The child does not need to investigate or prove the threat. Responsibility belongs to the person making the unsafe request.
Why is an expensive gift not evidence that a request for secrecy is safe?
Compare the reasoning after trying
A gift does not remove pressure or an unsafe request. Look at the behavior, not the gift or the person’s status.
With Q fixed at 12 model volume units per second, divide 12 by the area. At area 3, speed is 4.
A worked example
A fictional workshop compares water flowing through wide and narrow sections of a pipe. The flow stays steady, the liquid is incompressible, and there is no leak. Across each section, the same volume passes each second. You will change the area and watch the model speed respond.
If Q = 12 and area A = 3, what is model speed v?
Reasoning: 12 ÷ 3 = 4. This calculation comes from continuity, not from Bernoulli alone.
Deeper explanation
Continuity gives Q = A × v: volume flow equals cross-sectional area times average speed. In an ideal steady flow at equal height, Bernoulli connects pressure and speed. Real pipes and blood vessels also have losses, compliance, pumps, and unsteady flow. Faster does not universally mean lower pressure.
Try without looking
In the fixed-flow model, Q is 18 and area is 6. What is speed? Explain the calculation.
Compare the reasoning after trying
Speed is 18 ÷ 6 = 3 model speed units. This assumes steady, incompressible flow with no leak.
Could that one calculation tell you whether a real ventilation system is safe?
Compare the reasoning after trying
No. You would also need information about losses, leaks, fan performance, heat transfer and design requirements. A simplified model is not a safety certification.
Check all three requirements. One high score does not compensate for failing a required criterion.
A worked example
You are designing a fictional costume-workshop garment. The brief asks for at least 6 flexibility points and 5 splash-resistance points, with at most 8 cost tokens. These invented scores are only for this game. They do not certify protective clothing. Compare the swatches and choose evidence that meets the brief.
Which swatch meets flexibility ≥ 6, splash resistance ≥ 5, and cost ≤ 8?
Reasoning: B meets every listed requirement. A misses splash resistance; C misses flexibility and cost.
Deeper explanation
Engineering compares evidence against criteria and constraints. “Best material” depends on purpose. Cleanroom clothing controls contamination; pressure suits, fire protection, medical gowns, and fashion garments solve different problems.
Try without looking
Material X costs 4 tokens but fails a required splash score. Material Y costs 7 and meets every requirement. The budget is 8. Which meets the brief?
Compare the reasoning after trying
Y meets the brief. A lower price does not compensate for failing a required property.
Why might the material that works for a costume fail for a protective suit?
Compare the reasoning after trying
The purposes, hazards and required evidence differ. Invented game scores cannot establish real protective performance.
Human comfort · Heat transfer · Materials · Fashion · Buildings
Why does a jacket keep you warm?
Start here
Temperature tells us how hot or cold something is. Heat is energy transferred because of a temperature difference. A material can slow that transfer.
A worked example
Your body releases heat. On a cold day, clothing can slow its transfer to the surroundings. A jacket’s structure matters: thickness, trapped air, fit, and moisture affect how it performs.
A layer becomes twice as thick. Everything else in our conduction model stays the same. What happens?
Reasoning: Thickness is in the denominator: doubling it halves the predicted conduction rate.
Deeper explanation
In a simple steady conduction model, heat-transfer rate is proportional to thermal conductivity, area, and temperature difference, and inversely proportional to thickness. Real clothing also exchanges heat through moving air and radiation. An insulation calculation describes one part of a larger system.
Try without looking
In the same conduction model, a layer becomes four times as thick. What fraction of the original rate remains?
Compare the reasoning after trying
One quarter, or 25%. Rate is inversely proportional to thickness when material, area and temperature difference stay fixed.
What connects jacket insulation to building insulation, and where does the comparison stop?
Compare the reasoning after trying
Both can slow heat transfer. Real performance also depends on factors such as moving air, moisture, construction and temperature differences. The simplified calculation is only part of the system.
Hearing · Vibration · Number patterns · Music · Communication
How does a vibration become a sound?
Start here
A repeating motion is a vibration. Frequency counts how many cycles occur in one second. One cycle per second is one hertz (Hz). You can study this visually; hearing audio is not required.
A worked example
Sound can travel as a disturbance through air. In hearing, the ear receives vibration and converts it into signals that travel to the brain. Frequency helps describe pitch; it is different from how loud a sound is.
A tone changes from 220 Hz to 440 Hz. What is established?
Reasoning: 440 ÷ 220 = 2. Frequency counts cycles; that ratio alone says nothing about loudness or individual hearing.
Deeper explanation
A pure tone has one frequency. Musical sounds usually contain several frequency components. Doubling the fundamental frequency corresponds to an octave in standard musical tuning. Sound level and frequency describe different features, and listening involves more than either number alone.
Try without looking
A vibration changes from 300 cycles each second to 900. What changed by a factor of three?
Compare the reasoning after trying
Frequency tripled: 900 ÷ 300 = 3. That does not establish triple loudness.
How could someone study frequency without listening to a sound?
Compare the reasoning after trying
Count repeating cycles over time using a visual or numerical representation. Hearing audio is not required to understand the rate.
Human movement · Levers · Mathematics · Tools · Accessible design
Why does the place you push matter?
Start here
A force is a push or pull. A pivot is a point something turns around. Distance from that pivot affects the turning effect.
A worked example
A push can turn an object around a pivot. With the same sideways push, acting farther from the pivot creates more turning effect. Bones and muscles can be studied using lever models, with joints acting as pivots.
Move the same perpendicular force from 0.2 m to 0.4 m from the pivot. What changes?
Reasoning: Torque = force × distance in this model. Doubling distance while keeping force constant doubles torque.
Deeper explanation
Torque measures a force’s turning effect. Its magnitude is force × distance from the pivot × sin(angle between the force and that distance). Our model holds the force perpendicular, so torque = force × distance. Real joints involve multiple forces and changing geometry.
Try without looking
A perpendicular 12 N force acts 0.5 m from a pivot. What is the turning effect?
Compare the reasoning after trying
Torque is 12 × 0.5 = 6 N·m. The stated perpendicular angle matters.
Why can a longer handle make turning easier, and what does this model not prove?
Compare the reasoning after trying
The same perpendicular force farther from the pivot produces more torque. That alone does not establish whether a real tool is safe for a particular person or task.
This is an educational prototype, not a validated curriculum, intelligence test, or clinical service. Completion counts do not prove understanding.
Before teaching, ask the learner to explain a related problem. Allow their preferred communication method.
After the lesson, use a different example without answer choices. Ask what stays the same and what changes.
Return on a later day. Check whether the learner can still explain the idea without the worked example.
Record which support was needed: example, hint, or independent explanation. Do not turn this into a public ranking.
Ask what was confusing, inaccessible, culturally unfamiliar, or discouraging. Improve the material before expanding it.
A useful explanation identifies the idea, uses evidence, applies it to the new setting, and acknowledges a limit. This is a discussion rubric, not a standardized score. Formal research with children needs appropriate consent, privacy protections, and review; this page does not authorize a study.
These design choices draw on the Institute of Education Sciences learning practice guide; that guidance does not validate this particular website. Content and usability review, reviewed translations, and learner testing are still needed.