The Mistake Lab

Maths homework · CBSE Classes 6–8 · 10 minutes each

12 + 13 = 25 56!

A confident character makes a classic maths mistake. You catch it. Predict what happens, experiment on your phone, explain why — then prove it on brand-new problems.

For teachers

How to use these as homework

Assigning
  1. Share one experiment link in your class WhatsApp group. No login, app or adult help needed. Works on any phone browser.
  2. Students finish in 5–10 minutes and tap Send to teacher. You get a short text report.
  3. Next class: ask "What did Turbo / Dinesh / Gappu get wrong, and how did you prove it?" Let students who predicted wrongly explain what changed their mind.
Reading the report
  • My prediction shows the misconception before the experiment. A "Certain" wrong prediction is the most valuable one to discuss.
  • Transfer (first set) is the key number: fresh, randomized problems, first try only. 4/5 or 5/5 means the idea has moved to new problems.
  • Later sets show students who kept practising after feedback — effort worth praising.
  • In my words is their own explanation. It's the best evidence of understanding and hard to fake.
What if students use AI or copy?

Transfer numbers change for every student and every attempt, so copied answers don't carry over. Predictions are recorded before the reveal and never graded. The experiments ask students to notice things on an interactive model — an AI can tell them an answer, but it can't do the noticing for them. The own-words explanation is the best place to look for genuine understanding.

Privacy

Nothing leaves the student's phone unless they choose to send their report. Progress is stored only in that phone's browser.