Five children. Each has a hidden learning level and a hidden misconception. You get six turns. You teach blind — then the X-ray turns on and you see what you walked past.
A trainee teacher can fail this classroom a hundred times before ever meeting a real child. Reading levels use the ASER 2024 bands, and the spread across these five is the documented finding that learning levels inside one nominal grade span about seven grade-equivalents. The maths bugs are the classic documented subtraction errors: smaller-from-larger, and borrowing across a zero.
This page replays one recorded lesson so you can see the whole arc with no setup and no API key. To teach a class of your own — where Claude improvises all five children in response to whatever you actually say — open the live version (needs your own Anthropic key).
The lesson is replayed above with what each child was actually thinking — the thing a real teacher never gets to see. Their hidden profiles are below, and the coaching report follows.