Class 3 Computational Thinking & AI
Official CBSE Student Handbook curriculum with 280 interactive practice questions (20 questions per chapter), pattern recognition puzzles, cipher wheels, spatial 3D views, and step-by-step logic solutions.
What's in a Name?
What's in a Name? introduces foundational cryptography through Caesar Ciphers, letter shift wheels, secret messages, and word decomposition logic.
Practice Questions (20)
Click an option to test your solutionFind the largest number name that is hidden as continuous letters in the series: FORHLKLTEMELEVENDSKLFOURSDGSTWENTYSJLSIXTKSEVENL
Hint: Find the number words in the text: ELEVEN, FOUR, TWENTY, SIX, SEVEN. Which has the largest value?
Roy's favourite number has: • 3 letters in its name • The number of vowels is double the number of consonants in its name What is Roy's favourite number?
Hint: 'ONE' has 2 vowels (O, E) and 1 consonant (N). 2 is double of 1.
Boxes follow a theme: [8, 5 → FIVE8], [4, 2 → FOUR2], [6, 7 → SIX7], [9, 3 → ?]. What will come in place of '?'
Hint: Word of 1st number + Digit of 2nd number: NINE + 3 = NINE3.
Theme: [One-3 → 1 2 3], [Six-4 → 6 7 8 9], [Three-5 → 3 4 5 6 7]. What will come in place of '?' for [Four-3 → ?]?
Hint: Start at 4 and write 3 consecutive numbers: 4, 5, 6.
In a 2×2 shape reduction matrix where multiple small shapes inside a box reduce to the single dominant unique polygon: [Triangles → Triangle], [Pentagons → Pentagon], [Squares → Square], [Diamonds → ?]. What comes in place of '?'
Hint: Identify the common geometric shape inside the box.
Find the odd one out among: (a) Motorcycle, (b) Aeroplane, (c) Scooter, (d) Car.
Hint: Aeroplane flies in the air; all others travel on road.
Which of the following number names will come SECOND if arranged in dictionary (alphabetical) order: 5 (FIVE), 6 (SIX), 8 (EIGHT), 9 (NINE)?
Hint: Dictionary order: EIGHT → FIVE → NINE → SIX. Second is FIVE.
Letters inside circles: {E, F, V, X, I, S, N, O, N}. Spelling of which number can be formed using ONLY the circle letters?
Hint: S, I, X spells SIX (6).
Which number name appears in exact consecutive letter order in the string: 'TWLVETOWELEVENSVENTHREEIFEIHGT'?
Hint: Find the exact unbroken word: THREE is in '...VENTHREEIFE...'.
Using the letters {G, Y, T, H, E, R}, which of the following numbers CANNOT be spelt (letters can be repeated)?
Hint: ELEVEN requires letters L and V, which are not in the set.
In a Caesar Cipher with a shift of +3 (A → D, B → E, C → F): What is the encrypted message for 'CAT'?
Hint: Shift each letter 3 places forward: C → F, A → D, T → W.
If you write the numbers in words, which one has EXACTLY ONE vowel in its spelling?
Hint: 'SIX' has only 1 vowel (I).
X is a single-digit number (0 to 9). If X has EXACTLY 5 letters in its spelling, how many different values can X have?
Hint: THREE (5), SEVEN (5), EIGHT (5). Total = 3 numbers.
What is the secret message if 'KHOOR' is decoded with a Caesar Cipher shift of 3 backward (-3)?
Hint: K → H, H → E, O → L, R → O = HELLO.
How many letters are in the number name for 100 ('ONE HUNDRED') excluding spaces?
Hint: ONE (3) + HUNDRED (7) = 10 letters.
Which number name contains all of the letters: E, I, G, H, T?
Hint: All three words start with the root 'EIGHT'.
If A=1, B=2, C=3... Z=26, what is the letter sum of the word 'CAB'?
Hint: 3 + 1 + 2 = 6.
Which letter appears most frequently in the word 'MATHEMATICS'?
Hint: M=2, A=2, T=2.
What 4-letter number name starts with 'Z' and ends with 'O'?
Hint: The number 0 is spelt Z-E-R-O.
If 'DOG' is coded as 'EPH' (+1 shift), how is 'CAT' coded?
Hint: C + 1 = D, A + 1 = B, T + 1 = U → DBU.
The Thinking Spot: Movie Days Deduction
Raj, Aryan, and Rahul went to a movie on different days. Raj did not go on Monday, Wednesday, or Thursday. Aryan went on Friday, and Rahul went on Sunday.
Question: Which of the following days could Raj have gone to the movie?