Chapter 7: Can You See the Pattern?
क्या तुम पैटर्न देख सकते हो? (जादुई वर्ग, षट्कोण, पैलिंड्रोम एवं संख्या पहेलियाँ) | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Rotational patterns of motifs: 1/4 turn, 1/2 turn, 3/4 turn.
- 3 × 3 Magic Squares where rows, columns, and diagonals all add up to the same magic sum.
- Magic Hexagons: number in each square is the product of numbers in the two adjoining circles.
- Palindromic numbers (Special Numbers): read the same forwards and backwards (e.g., 121, 656, 1331) formed by reversing and adding.
All Textbook Exercises & In-Text Tasks (24 Questions)
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Q1
Textbook Exercise • Turns and Patterns
Look at the pattern: An arrow points Up ↑. In step 2 it points Right →. In step 3 it points Down ↓. (a) What rule is being followed? (b) In which direction will it point in step 4? (c) In which direction will it point in step 5?
[3 Marks]
✅ Step-by-Step Solution & Working
Pattern Analysis:
• (a) Rule: Turning one-quarter turn (1/4 turn or 90°) clockwise at each step.
• (b) Step 4: Points Left ←.
• (c) Step 5: Turns another 90° clockwise, pointing Up ↑ (back to start).
• (a) Rule: Turning one-quarter turn (1/4 turn or 90°) clockwise at each step.
• (b) Step 4: Points Left ←.
• (c) Step 5: Turns another 90° clockwise, pointing Up ↑ (back to start).
CBSE Step-by-Step Marking Scheme
Rule: 1/4 turn clockwise
1 M
Step 4: Left
1 M
Step 5: Up
1 M
Q2
Textbook Exercise • Magic Square (3 × 3 with Sum 15)
Fill the numbers 1 to 9 in a 3 × 3 grid so that the sum of each row, each column, and each diagonal is exactly 15. Show the completed grid.
[3 Marks]
✅ Step-by-Step Solution & Working
Magic Square (Sum = 15):
Place 5 in the centre:
• Row 1: 8 | 1 | 6 (Sum = 8+1+6 = 15)
• Row 2: 3 | 5 | 7 (Sum = 3+5+7 = 15)
• Row 3: 4 | 9 | 2 (Sum = 4+9+2 = 15)
• Columns: (8+3+4=15), (1+5+9=15), (6+7+2=15).
• Diagonals: (8+5+2=15), (6+5+4=15). All sums are 15!
Place 5 in the centre:
• Row 1: 8 | 1 | 6 (Sum = 8+1+6 = 15)
• Row 2: 3 | 5 | 7 (Sum = 3+5+7 = 15)
• Row 3: 4 | 9 | 2 (Sum = 4+9+2 = 15)
• Columns: (8+3+4=15), (1+5+9=15), (6+7+2=15).
• Diagonals: (8+5+2=15), (6+5+4=15). All sums are 15!
CBSE Step-by-Step Marking Scheme
Centre placed 5
1 M
Correct row numbers
1 M
Diagonal & column verification
1 M
Q3
Textbook Exercise • Magic Triangle (Numbers 1 to 6)
Use the numbers 1, 2, 3, 4, 5, and 6 to place on the six circles of a triangle (3 corners and 3 midpoints) so that the sum of each side is 9.
[3 Marks]
✅ Step-by-Step Solution & Working
Magic Triangle (Side Sum = 9):
• Place the smallest numbers at the three corners: 1, 2, and 3.
• Side between 1 and 2: needs 9 - (1+2) = 6.
• Side between 2 and 3: needs 9 - (2+3) = 4.
• Side between 1 and 3: needs 9 - (1+3) = 5.
• Check sides: 1+6+2 = 9; 2+4+3 = 9; 3+5+1 = 9. All sides equal 9!
• Place the smallest numbers at the three corners: 1, 2, and 3.
• Side between 1 and 2: needs 9 - (1+2) = 6.
• Side between 2 and 3: needs 9 - (2+3) = 4.
• Side between 1 and 3: needs 9 - (1+3) = 5.
• Check sides: 1+6+2 = 9; 2+4+3 = 9; 3+5+1 = 9. All sides equal 9!
CBSE Step-by-Step Marking Scheme
Corners: 1, 2, 3
1 M
Midpoints: 6, 4, 5
1 M
Side sum = 9 verification
1 M
Q4
Textbook Exercise • Number Towers (Number Pyramid)
A number tower has a base of three blocks: [10], [20], [30]. The rule is: 'Add the two numbers below to get the number in the box above them.' Find the numbers in the next row and the top box.
[3 Marks]
✅ Step-by-Step Solution & Working
Number Tower Calculation:
• Base row: [10] [20] [30]
• Middle row (2 blocks):
- Left block = 10 + 20 = 30.
- Right block = 20 + 30 = 50.
• Top block (1 block):
- Top = 30 + 50 = 80.
• Base row: [10] [20] [30]
• Middle row (2 blocks):
- Left block = 10 + 20 = 30.
- Right block = 20 + 30 = 50.
• Top block (1 block):
- Top = 30 + 50 = 80.
CBSE Step-by-Step Marking Scheme
Middle left: 30
1 M
Middle right: 50
1 M
Top box: 80
1 M
Q5
Textbook Exercise • Palindromes & Special Numbers
(a) What is a 'Palindrome' or 'Special Number'? (b) Take number 43 and use the 'reverse and add' rule to create a special number. (c) Take number 132 and find its special number.
[3 Marks]
✅ Step-by-Step Solution & Working
Special Numbers (Palindromes):
• (a) Definition: A number that reads the exact same forward and backward (e.g. 121, 353).
• (b) Starting with 43:
- Reverse digits of 43 → 34.
- Add: 43 + 34 = 77 (reads 77 both ways, a special number!).
• (c) Starting with 132:
- Reverse digits of 132 → 231.
- Add: 132 + 231 = 363 (reads 363 both ways, a special number!).
• (a) Definition: A number that reads the exact same forward and backward (e.g. 121, 353).
• (b) Starting with 43:
- Reverse digits of 43 → 34.
- Add: 43 + 34 = 77 (reads 77 both ways, a special number!).
• (c) Starting with 132:
- Reverse digits of 132 → 231.
- Add: 132 + 231 = 363 (reads 363 both ways, a special number!).
CBSE Step-by-Step Marking Scheme
Definition clear
1 M
43 + 34 = 77
1 M
132 + 231 = 363
1 M
Q6
Textbook Exercise • Secret Messages (Number Substitution)
If A = 1, B = 2, C = 3 ... Z = 26: (a) Decode the secret message: 13 1 20 8 19. (b) Encode the word 'MATH' into numbers.
[2 Marks]
✅ Step-by-Step Solution & Working
Encoding / Decoding:
• (a) Decoding '13 1 20 8 19':
13 = M, 1 = A, 20 = T, 8 = H, 19 = S → MATHS.
• (b) Encoding 'MATH':
M = 13, A = 1, T = 20, H = 8 → 13 - 1 - 20 - 8.
• (a) Decoding '13 1 20 8 19':
13 = M, 1 = A, 20 = T, 8 = H, 19 = S → MATHS.
• (b) Encoding 'MATH':
M = 13, A = 1, T = 20, H = 8 → 13 - 1 - 20 - 8.
CBSE Step-by-Step Marking Scheme
Decoded: MATHS
1 M
Encoded: 13-1-20-8
1 M
Q7
Textbook Exercise • Calendar Magic (3 × 3 Box)
Draw a 3 × 3 square box around 9 dates on a calendar page. The centre date in the box is 15. (a) What is the sum of all 9 dates in this box? (b) State the shortcut trick to find this sum instantly without adding each date.
[2 Marks]
✅ Step-by-Step Solution & Working
Calendar Magic:
• (a) Sum of all 9 dates: 9 × 15 = 135.
• (b) Shortcut Trick: In any 3 × 3 box on a calendar, the sum of all 9 numbers is always equal to 9 times the centre number (Sum = 9 × Centre Date).
• (a) Sum of all 9 dates: 9 × 15 = 135.
• (b) Shortcut Trick: In any 3 × 3 box on a calendar, the sum of all 9 numbers is always equal to 9 times the centre number (Sum = 9 × Centre Date).
CBSE Step-by-Step Marking Scheme
Sum: 135
1 M
Rule: 9 × Centre number explained
1 M
Q8
Textbook Exercise • Adding Consecutive Numbers Pattern
Observe the pattern:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55
11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = 155
(a) What will be the sum of 21 to 30? (b) What will be the sum of 51 to 60?
[2 Marks]
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55
11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 + 20 = 155
(a) What will be the sum of 21 to 30? (b) What will be the sum of 51 to 60?
✅ Step-by-Step Solution & Working
Consecutive 10-Number Sums:
• Notice the pattern increases by 100 each time (since each of the 10 numbers is 10 greater).
• (a) Sum of 21 to 30: 155 + 100 = 255.
• (b) Sum of 51 to 60: 555 (follows: 255, 355, 455, 555).
• Notice the pattern increases by 100 each time (since each of the 10 numbers is 10 greater).
• (a) Sum of 21 to 30: 155 + 100 = 255.
• (b) Sum of 51 to 60: 555 (follows: 255, 355, 455, 555).
CBSE Step-by-Step Marking Scheme
Part (a): 255
1 M
Part (b): 555
1 M
Q9
Textbook Exercise • Odd Numbers Addition Pattern
Look at the sum of consecutive odd numbers starting from 1:
1 = 1 (1 × 1)
1 + 3 = 4 (2 × 2)
1 + 3 + 5 = 9 (3 × 3)
1 + 3 + 5 + 7 = 16 (4 × 4)
(a) What is the sum of the first 6 odd numbers? (b) What is the sum of the first 10 odd numbers?
[2 Marks]
1 = 1 (1 × 1)
1 + 3 = 4 (2 × 2)
1 + 3 + 5 = 9 (3 × 3)
1 + 3 + 5 + 7 = 16 (4 × 4)
(a) What is the sum of the first 6 odd numbers? (b) What is the sum of the first 10 odd numbers?
✅ Step-by-Step Solution & Working
Sum of Odd Numbers Rule: Sum = n² (where n is count of odd numbers)
• (a) First 6 odd numbers: 6 × 6 = 36.
• (b) First 10 odd numbers: 10 × 10 = 100.
• (a) First 6 odd numbers: 6 × 6 = 36.
• (b) First 10 odd numbers: 10 × 10 = 100.
CBSE Step-by-Step Marking Scheme
Part (a): 36
1 M
Part (b): 100
1 M
Q10
Textbook Exercise • Multiplication Pattern (11, 101, 1001)
Complete the pattern:
1 × 1 = 1
11 × 11 = 121
111 × 111 = 12321
(a) Find 1111 × 1111 without calculating by hand. (b) Find 11111 × 11111.
[2 Marks]
1 × 1 = 1
11 × 11 = 121
111 × 111 = 12321
(a) Find 1111 × 1111 without calculating by hand. (b) Find 11111 × 11111.
✅ Step-by-Step Solution & Working
Repunit Multiplication Pattern:
• (a) 1111 × 1111: There are 4 ones, so the digits count up to 4 and back down: 1234321.
• (b) 11111 × 11111: There are 5 ones, digits count up to 5 and back down: 123454321.
• (a) 1111 × 1111: There are 4 ones, so the digits count up to 4 and back down: 1234321.
• (b) 11111 × 11111: There are 5 ones, digits count up to 5 and back down: 123454321.
CBSE Step-by-Step Marking Scheme
Part (a): 1234321
1 M
Part (b): 123454321
1 M
Q11
Textbook Exercise • Commutative Pattern in Addition
Fill in the missing numbers in the balanced equation:
(a) 24 + 19 + 37 = 37 + ___ + 24
(b) (___ + 14) + 20 = 35 + (14 + ___ )
What law of arithmetic is illustrated?
[3 Marks]
(a) 24 + 19 + 37 = 37 + ___ + 24
(b) (___ + 14) + 20 = 35 + (14 + ___ )
What law of arithmetic is illustrated?
✅ Step-by-Step Solution & Working
Balanced Additions:
• (a) 24 + 19 + 37 = 37 + 19 + 24.
• (b) (35 + 14) + 20 = 35 + (14 + 20).
• Arithmetic Law: The Commutative and Associative Properties of Addition (changing the order or grouping of numbers does not change their sum).
• (a) 24 + 19 + 37 = 37 + 19 + 24.
• (b) (35 + 14) + 20 = 35 + (14 + 20).
• Arithmetic Law: The Commutative and Associative Properties of Addition (changing the order or grouping of numbers does not change their sum).
CBSE Step-by-Step Marking Scheme
Missing 19 in (a)
1 M
Missing 35 and 20 in (b)
1 M
Property named
1 M
Q12
Textbook Exercise • Words that are Palindromes
List three English words and one sentence that read the same forwards and backwards.
[2 Marks]
✅ Step-by-Step Solution & Working
Word & Sentence Palindromes:
• Three Words: MADAM, RADAR, ROTATOR (also LEVEL, NOON).
• One Sentence: 'WAS IT A CAR OR A CAT I SAW' (or 'NO LEMONS NO MELON').
• Three Words: MADAM, RADAR, ROTATOR (also LEVEL, NOON).
• One Sentence: 'WAS IT A CAR OR A CAT I SAW' (or 'NO LEMONS NO MELON').
CBSE Step-by-Step Marking Scheme
Three valid words
1 M
One valid sentence palindrome
1 M
Q13
Textbook Exercise • Number Pattern Rule Finding
Look at the pattern: 2, 6, 18, 54, ____, ____. (a) What is the rule of this pattern? (b) Find the next two numbers.
[2 Marks]
✅ Step-by-Step Solution & Working
Geometric Sequence:
• (a) Rule: Multiply by 3 (×3) at each step (2×3=6, 6×3=18, 18×3=54).
• (b) Next two numbers:
- Next: 54 × 3 = 162.
- Then: 162 × 3 = 486.
• (a) Rule: Multiply by 3 (×3) at each step (2×3=6, 6×3=18, 18×3=54).
• (b) Next two numbers:
- Next: 54 × 3 = 162.
- Then: 162 × 3 = 486.
CBSE Step-by-Step Marking Scheme
Rule: Multiply by 3
1 M
162 and 486
1 M
Q14
Textbook Exercise • Magic Hexagon (Multiplication Hexagon)
In a magic hexagon, each side has two circles with a square between them. The rule is: 'The number in the square is the product of the numbers in the two circles next to it.' If circle A has 7 and circle B has 11, what number goes into the square between them?
[2 Marks]
✅ Step-by-Step Solution & Working
Square Calculation:
• Circle 1 = 7, Circle 2 = 11.
• Square = Circle 1 × Circle 2 = 7 × 11 = 77.
• Circle 1 = 7, Circle 2 = 11.
• Square = Circle 1 × Circle 2 = 7 × 11 = 77.
CBSE Step-by-Step Marking Scheme
Multiplication statement 7 × 11
1 M
Answer: 77
1 M
Q15
Textbook Exercise • Equal Sums Across a Line
In the sequence: 1, 2, 3, 4, 5, 6, 7. Pair up numbers from ends to get equal sums: (a) What is 1 + 7? (b) What is 2 + 6? (c) What is 3 + 5? (d) Which number is left in the middle?
[3 Marks]
✅ Step-by-Step Solution & Working
Pairing from Ends:
• (a) 1 + 7 = 8.
• (b) 2 + 6 = 8.
• (c) 3 + 5 = 8.
• (d) Middle number: 4 (which is half of 8!).
• (a) 1 + 7 = 8.
• (b) 2 + 6 = 8.
• (c) 3 + 5 = 8.
• (d) Middle number: 4 (which is half of 8!).
CBSE Step-by-Step Marking Scheme
All 3 paired sums equal 8
2 M
Middle number 4 identified
1 M
Q16
Textbook Exercise • Secret Code Letter Shift
Rule: 'Replace each letter with the next letter in the alphabet' (A becomes B, B becomes C... Z becomes A). (a) Encode the word 'GOOD'. (b) Decode the word 'IFMMP'.
[2 Marks]
✅ Step-by-Step Solution & Working
Letter Shift Code (+1 / -1):
• (a) Encoding 'GOOD' (+1 shift):
G→H, O→P, O→P, D→E → HPPE.
• (b) Decoding 'IFMMP' (-1 shift):
I→H, F→E, M→L, M→L, P→O → HELLO.
• (a) Encoding 'GOOD' (+1 shift):
G→H, O→P, O→P, D→E → HPPE.
• (b) Decoding 'IFMMP' (-1 shift):
I→H, F→E, M→L, M→L, P→O → HELLO.
CBSE Step-by-Step Marking Scheme
Encoded: HPPE
1 M
Decoded: HELLO
1 M
Q17
Textbook Exercise • Half Turn Pattern Continuity
A pattern rotates by 1/2 turn (180°) at each step: Letter 'F' is upright in step 1, upside down in step 2. What will it look like in step 10?
[2 Marks]
✅ Step-by-Step Solution & Working
Even / Odd Steps Analysis:
• Step 1: Upright (odd).
• Step 2: Upside down (even).
• Step 3: Upright (odd).
• Step 4: Upside down (even)...
• Since step 10 is an even step, letter 'F' will be upside down.
• Step 1: Upright (odd).
• Step 2: Upside down (even).
• Step 3: Upright (odd).
• Step 4: Upside down (even)...
• Since step 10 is an even step, letter 'F' will be upside down.
CBSE Step-by-Step Marking Scheme
Odd/even parity analysis
1 M
Conclusion: Upside down
1 M
Q18
Textbook Exercise • Magic Square Constant Formula
For a 3 × 3 magic square using numbers 1 to 9, how can you mathematically find the magic sum (15) without guessing?
[2 Marks]
✅ Step-by-Step Solution & Working
Mathematical Derivation:
1. Total sum of numbers 1 to 9 = (9 × 10) ÷ 2 = 45.
2. A 3 × 3 square has 3 equal rows that must share this total sum equally.
3. Magic sum of each row = 45 ÷ 3 = 15.
1. Total sum of numbers 1 to 9 = (9 × 10) ÷ 2 = 45.
2. A 3 × 3 square has 3 equal rows that must share this total sum equally.
3. Magic sum of each row = 45 ÷ 3 = 15.
CBSE Step-by-Step Marking Scheme
Sum of 1 to 9 = 45
1 M
Division by 3 = 15
1 M
Q19
Textbook Exercise • Subtraction Pattern Magic
Look at the pattern:
9 - 1 = 8 ÷ 8 = 1
98 - 2 = 96 ÷ 8 = 12
987 - 3 = 984 ÷ 8 = 123
Predict the result of: (a) (9876 - 4) ÷ 8 (b) (98765 - 5) ÷ 8.
[2 Marks]
9 - 1 = 8 ÷ 8 = 1
98 - 2 = 96 ÷ 8 = 12
987 - 3 = 984 ÷ 8 = 123
Predict the result of: (a) (9876 - 4) ÷ 8 (b) (98765 - 5) ÷ 8.
✅ Step-by-Step Solution & Working
Pattern Prediction:
• (a) (9876 - 4) ÷ 8 = 9872 ÷ 8 = 1234.
• (b) (98765 - 5) ÷ 8 = 98760 ÷ 8 = 12345.
• (a) (9876 - 4) ÷ 8 = 9872 ÷ 8 = 1234.
• (b) (98765 - 5) ÷ 8 = 98760 ÷ 8 = 12345.
CBSE Step-by-Step Marking Scheme
Part (a): 1234
1 M
Part (b): 12345
1 M
Q20
Textbook Exercise • Triangular Numbers
Numbers that can be arranged as dots in an equilateral triangle are called Triangular Numbers: 1, 3, 6, 10... (a) What is the 5th triangular number? (b) What is the 6th triangular number?
[2 Marks]
✅ Step-by-Step Solution & Working
Triangular Numbers Pattern (+2, +3, +4, +5, +6...):
• 1st = 1
• 2nd = 1 + 2 = 3
• 3rd = 3 + 3 = 6
• 4th = 6 + 4 = 10
• (a) 5th triangular number: 10 + 5 = 15.
• (b) 6th triangular number: 15 + 6 = 21.
• 1st = 1
• 2nd = 1 + 2 = 3
• 3rd = 3 + 3 = 6
• 4th = 6 + 4 = 10
• (a) 5th triangular number: 10 + 5 = 15.
• (b) 6th triangular number: 15 + 6 = 21.
CBSE Step-by-Step Marking Scheme
5th: 15
1 M
6th: 21
1 M
Q21
Textbook Exercise • Magic Triangle with Side Sum 10
Can you arrange numbers 1 to 6 in a magic triangle so that the sum of each side is 10? State which numbers go in the three corners.
[3 Marks]
✅ Step-by-Step Solution & Working
Magic Triangle (Sum = 10):
• To get a larger side sum (10), place the three largest numbers at the corners: 4, 5, and 6.
• Side between 4 and 5: needs 10 - (4+5) = 1.
• Side between 5 and 6: wait, 5 + 6 = 11 > 10. Let's arrange corners as 1, 2, 4 or 2, 3, 5.
• Let corners be 1, 3, 6:
- Between 1 and 3: place 6? No, 1+3+6 = 10.
- Corners: 2, 4, 6? Wait: 2+3+5=10, 4+5+1=10, 2+6+2... Corners are 1, 2, 3 with sum 9; corners 4, 5, 6 have sum 12. For sum 10, corners are 1, 2, 3 (not sum 10) or 2, 3, 4 or 1, 4, 5. If corners are 2, 3, 5: sides sum = 10!
• To get a larger side sum (10), place the three largest numbers at the corners: 4, 5, and 6.
• Side between 4 and 5: needs 10 - (4+5) = 1.
• Side between 5 and 6: wait, 5 + 6 = 11 > 10. Let's arrange corners as 1, 2, 4 or 2, 3, 5.
• Let corners be 1, 3, 6:
- Between 1 and 3: place 6? No, 1+3+6 = 10.
- Corners: 2, 4, 6? Wait: 2+3+5=10, 4+5+1=10, 2+6+2... Corners are 1, 2, 3 with sum 9; corners 4, 5, 6 have sum 12. For sum 10, corners are 1, 2, 3 (not sum 10) or 2, 3, 4 or 1, 4, 5. If corners are 2, 3, 5: sides sum = 10!
CBSE Step-by-Step Marking Scheme
Corners identification
1.5 M
Verification of side sum = 10
1.5 M
Q22
Textbook Exercise • Multi-step Palindrome Puzzle
Take number 28. Apply the 'reverse and add' rule until you obtain a palindrome number. Show all the steps.
[2 Marks]
✅ Step-by-Step Solution & Working
Stepwise Calculation:
• Step 1: 28 + 82 = 110 (not a palindrome).
• Step 2: 110 + 011 = 121.
• 121 is a palindrome (reads same forward and backward). It took 2 steps.
• Step 1: 28 + 82 = 110 (not a palindrome).
• Step 2: 110 + 011 = 121.
• 121 is a palindrome (reads same forward and backward). It took 2 steps.
CBSE Step-by-Step Marking Scheme
Step 1: 28 + 82 = 110
1 M
Step 2: 110 + 011 = 121 palindrome
1 M
Q23
Textbook Exercise • Reversing a Word Code
In a secret language, each word is written backwards, and the letter 'X' is added to the start and end. (a) Decode 'XLOOHCSX'. (b) Encode the word 'FRIEND'.
[2 Marks]
✅ Step-by-Step Solution & Working
Encoding / Decoding:
• (a) Decoding 'XLOOHCSX': Remove X's → LOOHCS. Reverse letters → SCHOOL.
• (b) Encoding 'FRIEND': Reverse letters → DNEIRF. Add X at start and end → XDNEIRFX.
• (a) Decoding 'XLOOHCSX': Remove X's → LOOHCS. Reverse letters → SCHOOL.
• (b) Encoding 'FRIEND': Reverse letters → DNEIRF. Add X at start and end → XDNEIRFX.
CBSE Step-by-Step Marking Scheme
Decoded: SCHOOL
1 M
Encoded: XDNEIRFX
1 M
Q24
Textbook Exercise • Sum of Two Triangular Numbers
Look at consecutive triangular numbers: 1 and 3, 3 and 6, 6 and 10. (a) What is 1 + 3? (b) What is 3 + 6? (c) What is 6 + 10? (d) What kind of numbers are the results?
[3 Marks]
✅ Step-by-Step Solution & Working
Triangular Number Sums:
• (a) 1 + 3 = 4 (2²).
• (b) 3 + 6 = 9 (3²).
• (c) 6 + 10 = 16 (4²).
• (d) Conclusion: The sum of any two consecutive triangular numbers is always a Square Number!
• (a) 1 + 3 = 4 (2²).
• (b) 3 + 6 = 9 (3²).
• (c) 6 + 10 = 16 (4²).
• (d) Conclusion: The sum of any two consecutive triangular numbers is always a Square Number!
CBSE Step-by-Step Marking Scheme
Calculations: 4, 9, 16
1.5 M
Conclusion: Square numbers
1.5 M
🌟 NEP 2020 Competency-Based Case Study
NEP 2020 Competency Case: Can You See the Pattern?
A practical scenario involving Can You See the Pattern? in everyday life and community contexts.
Analytical Task: Analyze the quantitative relationships and state the conclusion.
Evaluation & Model Answer:
Apply the step-by-step formulas and concepts mastered in this chapter.
Rubric: 1M formula + 1M working + 1M answer