Lesson 0 of 13

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3 min

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Put four cards in a row: 3, 8, 1, 6. Each card shows one digit, from 0 to 9. Swap two cards: they change places. The number changes.

Same 4 digits. A new order. A new number.

Chapter 3 of your NCERT book is Number Play.

What you will learn

Rearranging digits. Swap the order. Get a new number.
Biggest and smallest. Build the biggest and smallest number you can.
Palindromes. A number that reads the same both ways.
Supercells. A number bigger than every neighbour that touches it.
Estimation. A fast answer that is close to the real one.
Number puzzles. Clues that leave only one hidden number.
6174. Biggest minus smallest, again and again.
Collatz. Even: halve (divide by 2). Odd: triple (multiply by 3) and add 1. Watch the numbers reach 1.
Number games. Work backwards to find a way to always win.