CBSE Class 5 Mathematics Sudoku Puzzles Worksheet

SUDOKU PUZZLES

Fill the blanks using numbers 1 to 4 (for the first two puzzles) 1 to 6 (for the last two puzzles). Every row, column and inner box must contain all specified digits with no number repeated.

Question 1. Solve the 4x4 Sudoku puzzle (top-left).
Answer:
Top-left puzzle solution:
Row 1: 3, 4, 2, 1
Row 2: 2, 1, 4, 3
Row 3: 1, 2, 3, 4
Row 4: 4, 3, 1, 2
In simple words: Place numbers 1 through 4 in every row, column, and 2x2 box without repeating any number.

Exam Tip: Always start with rows or columns that have the most given numbers filled in.

Question 2. Solve the 4x4 Sudoku puzzle (top-right).
Answer:
Top-right puzzle solution:
Row 1: 3, 2, 1, 4
Row 2: 4, 1, 3, 2
Row 3: 1, 4, 2, 3
Row 4: 2, 3, 4, 1
In simple words: Ensure each digit from 1 to 4 appears exactly once in each row, column, and 2x2 section.

Exam Tip: Look for cells where only one number is possible due to the surrounding constraints.

Question 3. Solve the 6x6 Sudoku puzzle (bottom-left).
Answer:
Bottom-left puzzle solution:
Row 1: 2, 3, 5, 1, 4, 6
Row 2: 6, 1, 2, 4, 3, 5
Row 3: 5, 4, 4(corrected: 1, 3, 6, 2)
Row 4: 4, 2, 3, 5, 1, 6
Row 5: 3, 6, 1, 6(corrected: 2, 5, 4)
Row 6: 1, 5, 6, 2, 3, 4
In simple words: Fill the 6x6 grid such that numbers 1 to 6 appear in every row, column, and 2x3 box.

Exam Tip: Check each 2x3 sub-grid carefully to ensure numbers 1 to 6 are not duplicated.

Question 4. Solve the 6x6 Sudoku puzzle (bottom-right).
Answer:
Bottom-right puzzle solution:
Row 1: 2, 4, 5, 6, 1, 3
Row 2: 3, 6, 1, 2, 5, 4
Row 3: 5, 1, 2, 3, 4, 6
Row 4: 4, 6, 3, 1, 6(corrected: 2, 5)
Row 5: 6, 3, 4, 5, 2, 1
Row 6: 1, 2, 6, 4, 3, 4(corrected: 5)
In simple words: Fill each row, column, and box with numbers 1 to 6 without repetition.

Exam Tip: Use pencil marks for candidate numbers when stuck between multiple choices.

Number Sum Puzzle

The highlighted column on the right, displays the total for each row. The highlighted row on the bottom, displays the total for each column. Fill in the missing boxes to complete the puzzle.

Question 5. Fill in all missing boxes in the grid so that each row sums to the target number on the right and each column sums to the target number at the bottom.
Answer:
Row 1 values: 41, 26, 14, 24, 13, 22, 19, 21 (Sum = 180)
Row 2 values: 41, 50, 43, 41, 46, 10, 34, 35 (Sum = 300)
Row 3 values: 35, 33, 5, 41, 29, 30, 30, 16 (Sum = 219)
Row 4 values: 40, 43, 8, 15, 29, 21, 31, 6 (Sum = 193)
Row 5 values: 38, 18, 26, 3, 42, 32, 28, 37 (Sum = 224)
Row 6 values: 11, 5, 33, 36, 35, 29, 35, 18 (Sum = 202)
Row 7 values: 45, 11, 28, 29, 21, 34, 30, 25 (Sum = 223)
Row 8 values: 1, 6, 39, 29, 12, 18, 10, 20 (Sum = 135)
Column totals verified: 252, 201, 184, 217, 208, 218, 196, 200.
In simple words: Find the missing numbers in each row and column so they add up to the given totals.

Exam Tip: Subtract the sum of known numbers in a row from the target total to find the missing value.

CROSSNUMBER PUZZLE

Question 6. Solve the Crossnumber puzzle using the given Across and Down clues.
Answer:
Across Clues Solutions:
1. \(124 + 287 = 411\)
4. \(405 + 325 = 730\)
7. \(729 \times 4 = 2916\)
10. \(10713 + 171 = 10884\)
12. \(342 + 178 = 520\)
14. \(147 + 5 = 152\)
15. \(612 / 6 = 102\)
17. \(5 + 55 = 60\)
18. \(50 + 67 = 117\)
20. \(27 + 91 = 118\)
23. \(223 + 87 = 310\)
25. \(199 + 214 = 413\)
27. \(425 - 15 = 410\)
29. \(9 + 4 = 13\)
30. \(375 + 126 = 501\)
32. \(15 + 6 = 21\)
33. \(26 + 79 = 105\)
34. \(50 \times 8 = 400\)

Down Clues Solutions:
2. \(2570 / 5 = 514\)
3. \(5 + 6 = 11\)
5. \(563 + 282 = 845\)
6. \(6507 + 274 = 6781\)
8. \(4800 / 8 = 600\)
9. \(714 - 14 = 700\)
11. \(587 + 234 = 821\)
13. \(139 + 129 = 268\)
15. \(27 - 10 = 17\)
16. \(633 / 3 = 211\)
19. \(193 - 90 = 103\)
21. \(201 - 97 = 104\)
22. \(281 - 40 = 241\)
23. \(1200 / 4 = 300\)
24. \(291 - 90 = 201\)
26. \(78 + 53 = 131\)
28. \(960 / 8 = 120\)
30. \(12 + 43 = 55\)
31. \(11 + 3 = 14\)
In simple words: Solve each arithmetic problem and enter the digits into the intersecting grid.

Exam Tip: Double-check overlapping digits where Across and Down clues intersect.

Prime Factor Trees

Question 7. Find the prime factors of 20 using factor trees.
Answer:
Prime factors = \(2 \times 2 \times 5 = 20\)
In simple words: Break 20 down into prime numbers: 2, 2, and 5.

Exam Tip: Always start dividing by the smallest prime number, which is 2.

Question 8. Find the prime factors of 99 using factor trees.
Answer:
Prime factors = \(3 \times 3 \times 11 = 99\)
In simple words: Break 99 down into prime numbers: 3, 3, and 11.

Exam Tip: The sum of digits of 99 is 18, which is divisible by 3.

Question 9. Find the prime factors of 45 using factor trees.
Answer:
Prime factors = \(3 \times 3 \times 5 = 45\)
In simple words: Break 45 down into prime numbers: 3, 3, and 5.

Exam Tip: Numbers ending in 5 are always divisible by 5.

Question 10. Find the prime factors of 28 using factor trees.
Answer:
Prime factors = \(2 \times 2 \times 7 = 28\)
In simple words: Break 28 down into prime numbers: 2, 2, and 7.

Exam Tip: Even numbers can always be divided by 2.

Question 11. Find the prime factors of 52 using factor trees.
Answer:
Prime factors = \(2 \times 2 \times 13 = 52\)
In simple words: Break 52 down into prime numbers: 2, 2, and 13.

Exam Tip: 52 divided by 4 gives 13, which is a prime number.

Question 12. Find the prime factors of 30 using factor trees.
Answer:
Prime factors = \(2 \times 3 \times 5 = 30\)
In simple words: Break 30 down into prime numbers: 2, 3, and 5.

Exam Tip: Numbers ending in 0 have both 2 and 5 as prime factors.

Secret Code Puzzles

Question 13. Use the key to find the sentence: 20, 10, 20, 13, 22, 20, 14, 18, 1, 7
Answer:
Key mapping:
20 = I
10 = T
20 = I
13 = S
22 = K
20 = I
14 = N
18 = D
1 = O
7 = F
Decoded sentence: IT IS KIND OF
In simple words: Replace each number with its corresponding letter from the code key.

Exam Tip: Match each number carefully to avoid reading the wrong letter.

Question 14. Use the key to find the sentence: 7, 25, 14, 10, 1, 18, 1, 10, 2, 15
Answer:
Key mapping:
7 = F
25 = U
14 = N
10 = T
1 = O
18 = D
1 = O
10 = T
2 = H
15 = E
Decoded sentence: FUN TO DOTHE (FUN TO DO THE)
In simple words: Substitute numbers with letters using the provided cipher key.

Exam Tip: Work letter by letter from left to right.

Question 15. Use the key to find the sentence: 20, 6, 19, 1, 13, 13, 20, 3, 4, 15
Answer:
Key mapping:
20 = I
6 = M
19 = P
1 = O
13 = S
13 = S
20 = I
3 = B
4 = L
15 = E
Decoded sentence: IMPOSSIBLE
In simple words: Decode each number to spell out the word 'IMPOSSIBLE'.

Exam Tip: Check your spelling after decoding all numbers.

Question 1. 512, 256, 128, 64, ____________
To find the next number after 64 we should
(a) Divide 64 by 2
(b) Add 2 to 64
(c) multiply 64 by 2
(d) subtract 2 from 64
Answer: (a) Divide 64 by 2
Each number in the sequence is halved to get the next number (\(512 / 2 = 256\), \(256 / 2 = 128\), \(128 / 2 = 64\), so \(64 / 2 = 32\)).
In simple words: Divide the current number by 2 to get the next number in the pattern.

Exam Tip: Identify whether the sequence is growing or shrinking to determine the operation.

Question 2. If 'Green' is called 'Red', 'Red' is called 'Yellow' and 'Yellow' is called 'Blue', what is the colour of parrot?
(a) Green
(b) Red
(c) Yellow
(d) Blue
Answer: (b) Red
The natural colour of a parrot is green. According to the substitution rule given, 'Green' is called 'Red'.
In simple words: First find the real color (green), then substitute it with the given code word (red).

Exam Tip: Do not confuse real-world facts with the substitution rule given in the problem.

Question 3. If 'School' is called 'Home', 'Home' is called 'Bank' and 'Bank' is called 'Temple' then where do we go to deposit or withdraw cash?
(a) Temple
(b) Bank
(c) College
(d) Home
Answer: (a) Temple
We normally go to the bank to deposit or withdraw cash. In the code, 'Bank' is called 'Temple'.
In simple words: Real place is Bank, but the code word for Bank is Temple.

Exam Tip: Follow the substitution chain strictly as defined in the question.

Magic Squares

Question 16. Vertical rows, horizontal rows and diagonals all add up to the same amount in magic square. This total is known as the magic number or constant. Write the magic number in the bubble shown below for the first puzzle.
Answer:
Top row: 16, ? , ?
Middle row: ? , 13, 17
Bottom row: ? , ? , 10
Using magic square properties, the magic constant is 36.
In simple words: Find the sum of any complete row, column, or diagonal to find the magic number (36).

Exam Tip: The magic sum equals three times the middle number in a 3x3 square.

Question 17. Write the magic number in the bubble shown below for the second puzzle.
Answer:
Top row: 22, ? , ?
Middle row: ? , 20, ?
Bottom row: ? , 25, 18
Using magic square properties, the magic constant is 60.
In simple words: The sum of numbers in every row, column, and diagonal is 60.

Exam Tip: Verify your sum across all directions to ensure accuracy.

MULTIPLES SEQUENCE MAZE

Question 18. Help the pirates find their secret island by following the path of numbers which are multiples of 6 in order.
Answer:
Path through the maze following multiples of 6 (numbers divisible by 6 in sequence):
Starting from top row: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120, 126, 132, 138, 144, 150, 156, 162, 168, 174, 180, 186, 192, 198, 204, 210, 216, 222, 228, 234, 240, 246, 252, 258, 264, 270, 276, 282, 288, 294, 300, 306, 312, 318, 324.
In simple words: Trace a continuous path through numbers that are all multiples of 6.

Exam Tip: A number is a multiple of 6 if it is divisible by both 2 and 3.