[ CBSE CLASS 6 / COMPUTATIONAL THINKING / CHAPTER 3 / 2026-27 ]

Class 6 Number Play: Computational Thinking Questions and Answers

The Number Play CT chapter turns number puzzles into small algorithms: follow a rule (reverse the digits, halve or triple-plus-one) and watch what happens. Students practise following steps exactly and spotting patterns in the results.

Practise 6 questions Printable worksheet
Skills: Algorithmic thinking · Pattern recognition · Decomposition · Linked to Ganita Prakash Chapter 3: Number Play

[ WORKED EXAMPLE ]

Which is the first palindrome year after 1991?

Answer: 2002.

  1. 1999 backwards is 9991, not the same.
  2. 2002 backwards is 2002, so it is a palindrome.
  3. No year between 1992 and 2001 is a palindrome, so 2002 is the first.

What this chapter is about

Number Play explores palindromes, digit sums, “supercells” in a grid and number-machine rules such as the Kaprekar routine and the Collatz sequence.

Each puzzle is a mini program: a rule applied again and again. The CT skill is to apply it carefully and notice where the process always ends up.

Students also reason about all possible arrangements of digits, an early form of systematic search.

[ PRACTICE MODE / 6 QUESTIONS ]

Try it yourself

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Pattern recognitionQuestion 1 of 6 · Score 0

Which is the first palindrome year after 1991?

Choose one answer

All Number Play questions with answers

Try each one first, then open it to check the answer and the reasoning.

Q1Which is the first palindrome year after 1991?
  • 1999
  • 2002
  • 2112
  • 2020

Answer: B. 2002

Hint: A palindrome reads the same forwards and backwards. Check each option.

  1. 1999 backwards is 9991, not the same.
  2. 2002 backwards is 2002, so it is a palindrome.
  3. No year between 1992 and 2001 is a palindrome, so 2002 is the first.

Skill: Pattern recognition · Level: easy · Report an error

Q2Arrange the digits of 4213 to make the largest and smallest numbers. What is largest − smallest?
  • 3087
  • 3078
  • 2997
  • 3197

Answer: A. 3087

Hint: Largest: digits in decreasing order. Smallest: digits in increasing order.

  1. Largest is 4321; smallest is 1234.
  2. 4321 − 1234 = 3087.
  3. Repeating this step with any 4-digit number (not all digits the same) eventually reaches 6174, Kaprekar’s constant.

Skill: Algorithmic thinking · Level: medium · Report an error

Q3Rule: if a number is even, halve it; if it is odd, multiply by 3 and add 1. Starting from 6, how many steps to reach 1?
  • 6
  • 7
  • 8
  • 9

Answer: C. 8

Hint: Write the whole chain and count the arrows.

  1. 6 → 3 → 10 → 5 → 16 → 8 → 4 → 2 → 1.
  2. Count the arrows: there are 8.
  3. So it takes 8 steps.

Skill: Algorithmic thinking · Level: medium · Report an error

Q4The digits of a number add up to 9. Which must be true?
  • It is even
  • It is divisible by 9
  • It is a palindrome
  • It has two digits

Answer: B. It is divisible by 9

Hint: Test a few: 18, 27, 108, 333.

  1. 18, 27, 108 and 333 all have digit sum 9.
  2. All of them divide exactly by 9; not all are even or palindromes, and they have different numbers of digits.
  3. A number is divisible by 9 when its digit sum is divisible by 9.

Skill: Abstraction · Level: medium · Report an error

Q5A cell is a “supercell” if its number is bigger than its neighbours. In the row 23 | 41 | 18 | 56 | 37, how many supercells are there?
  • 1
  • 2
  • 3
  • 4

Answer: B. 2

Hint: Check each cell against the cells to its left and right only.

  1. 23 < 41, so no. 41 > 23 and 41 > 18, so yes.
  2. 18 is smaller than both neighbours, so no. 56 > 18 and 56 > 37, so yes.
  3. 37 < 56, so no. There are 2 supercells.

Skill: Decomposition · Level: medium · Report an error

Q6How many different 3-digit numbers can you make using the digits 1, 2 and 3 once each?
  • 3
  • 6
  • 9
  • 27

Answer: B. 6

Hint: Fix the first digit, then list the ways to arrange the other two.

  1. Starting with 1: 123, 132. Starting with 2: 213, 231.
  2. Starting with 3: 312, 321.
  3. 3 choices × 2 arrangements = 6 numbers.

Skill: Algorithmic thinking · Level: easy · Report an error

Frequently asked questions

What does the Class 6 Number Play Computational Thinking chapter cover?

The Number Play CT chapter turns number puzzles into small algorithms: follow a rule (reverse the digits, halve or triple-plus-one) and watch what happens. Students practise following steps exactly and spotting patterns in the results.

Which computational thinking skills does Number Play use?

Number Play mainly practises algorithmic thinking, pattern recognition, decomposition. It links to Ganita Prakash Chapter 3: Number Play.

Where are the official CBSE Number Play questions?

The official questions are in the CBSE Class 6 Computational Thinking and AI handbook for 2026-27, free on the CBSE Academic website. The practice on this page is original and mapped to the same chapter.

More Class 6 chapters