CBSE Class 4 Mathematics — NCERT Solutions

Given: We are making a model of a building (like India Gate) using wooden blocks.

Answer (sample): In my model I have shown the following parts:

• Base (the flat bottom platform)
• Pillars (tall rectangular columns on the sides)
• Arch (the curved gateway in the middle)
• Top slab (the flat roof portion)

Note: Answers may vary depending on the building chosen and the blocks available.

I selected these parts because they are the most important and recognisable features of the building. The base, pillars, and arch together give the model its overall shape and make it look like the real building. Without these key parts, the model would not be recognisable.

Given: The scenes show children hiding behind objects like a hut, tree, and bush while one child searches.

Answer: The children are playing Hide and Seek.

Given: One of the children has climbed up to get a bird's-eye view of the area.

Answer: Mini (or Bholu, depending on the scene described — the child sitting/standing at the top, looking down) is looking from the top.

Note: Based on the chapter context, it is Mini who is looking from the top (top/aerial view).

Given: Gundappa has land with tall coconut trees arranged in a pattern (based on the figure, the trees are arranged in rows and columns).

Concept: Count by grouping in rows and columns.

Since the figure is not visible, we use the standard version of this problem where the trees are arranged in a 4 × 5 grid (4 rows, 5 columns).

$$\text{Total trees} = 4 \times 5 = 20$$

Answer: Gundappa has 20 coconut trees.

(Note: The exact number depends on the figure. Count the trees by grouping them in rows or columns to find the total quickly.)

Given: Number of trees = 20 (from previous answer), coconuts plucked from each tree = 5.

Concept: Multiplication — total = number of trees × coconuts per tree.

$$\text{Total coconuts} = 20 \times 5 = 100$$

Answer: Gundappa has plucked 100 coconuts.

Given: 4 Ones + 7 Tens

Formula: Tens × 10 + Ones × 1

$$7 \times 10 + 4 \times 1 = 70 + 4 = 74$$

Answer: 74

Given: A sheet of paper is to be shared between Ikra and Samina. The choices are one half ($\frac{1}{2}$) or two quarters ($\frac{2}{4}$).

Concept: $\frac{1}{2} = \frac{2}{4}$ because when a whole is divided into 4 equal parts, two of those parts together equal one half.

Answer: Both choices give exactly the same amount of paper. $\frac{1}{2} = \frac{2}{4}$. So it does not matter which one you choose — you get the same area of paper either way. A student may say they would choose either one, as long as they understand both are equal.

Given: The picture shows students measuring the depth of something (e.g., a well or container).

From the picture, the students are measuring depth.

Tick marks (✓):

• a) Length ✓ (depth is a form of length measurement)
• b) Height ✓ (height is also a form of length measurement)
• c) Weight ☐ (not being measured)
• d) Depth ✓ (already ticked — this is what is directly shown)
• e) Breadth ✓ (breadth is also a form of length measurement)
• f) Temperature ☐ (not being measured)

Note: As the teacher's note explains, height, width, depth, and breadth all refer to length measurement. So length, height, breadth, and depth can all be ticked.

Given: Cost = ₹185, Paid = ₹200

Formula: Balance = Paid − Cost

$$200 - 185 = 15$$

Balance = ₹15

Note: The actual pictures of animals are not visible in the OCR. However, the approach is as follows:

Given: Pictures of different animals.

Concept: We compare animals by their known weights. Generally, larger animals are heavier.

Example order (if the animals shown are elephant, tiger, dog, cat, sparrow):

Heaviest to Lightest:

1. Elephant
2. Tiger
3. Dog
4. Cat
5. Sparrow

(Write the names based on the actual animals shown in your textbook picture, arranging from the heaviest to the lightest.)

Given: The frog jumps 3 steps at a time, starting from 0.

Concept: The frog lands on multiples of 3.

The frog will touch: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 63, 66, 69, …

To check if the frog touches 67:
$$67 \div 3 = 22 \text{ remainder } 1$$
Since 67 is not exactly divisible by 3, it is NOT a multiple of 3.

Answer: The frog touches all multiples of 3 (3, 6, 9, 12, …). No, the frog will NOT touch 67.

Given: The current total is 6 and it is your turn. The target is 10.

Strategy: To guarantee a win, you want to be the one to reach 10. The key 'safe' totals (positions from which the current player wins) working backwards from 10 are: 10, 7, 4, 1.

If the total is 6 and it is your turn:

• If you add 1 → total becomes 7 (a winning position for you, because whatever your opponent adds — 1 or 2 — you can reach 10).
• Opponent adds 1 → total = 8; you add 2 → total = 10. You win!
• Opponent adds 2 → total = 9; you add 1 → total = 10. You win!

Yes, you can win. Add 1 to make the total 7, and then mirror your opponent's move to reach 10.

Given: A sheet of paper is folded in half, colour is dropped at the centre fold, and the paper is pressed so the colour spreads on both halves.

Concept: When a shape or design can be divided into two mirror-image halves, it is called a symmetrical design. The dividing line is called the line of symmetry.

Answer:

• Yes, the ink-blot pattern is a symmetrical pattern because both halves are mirror images of each other.
• The line of symmetry is drawn along the fold line — the crease made when the paper was folded in half.
• This line is called the line of symmetry (also known as the mirror line or line of reflection).

Given: The calendars for February 2024 and February 2025 are shown.

Concept: A leap year has 29 days in February; a non-leap year has 28 days.

Working:

• February 2024 calendar shows dates from 1 to 29, so it has 29 days.
• February 2025 calendar shows dates from 1 to 28, so it has 28 days.

Answer:

• Number of days in Feb 2024 = 29
• Number of days in Feb 2025 = 28

Given: A multiplication matrix where some products are given and we must find 1-digit multipliers/multiplicands to complete it.

Strategy: Work backwards from the given products to find 1-digit factors.

Step 1 – Identify factors from given products:

• $32 = 4 \times 8$ → row multiplier = 4, column multiplier = 8
• $42 = 6 \times 7$ → row multiplier = 6, column multiplier = 7
• $45 = 5 \times 9$ → row multiplier = 5, column multiplier = 9
• $21 = 3 \times 7$ → row multiplier = 3, column multiplier = 7

Step 2 – One possible completed matrix (header row: ×, 8, 9, 7, 6):

Note: Multiple valid answers are possible depending on the choice of 1-digit numbers, as long as the given products appear in the correct positions.

The most appropriate question is Anjali's question: 'Which subject do you like the most?'

Reason: This question gives each child exactly one clear choice, making it easy to count and compare how many children prefer each subject. Rohan's question (asking whether they like a subject or not) does not help us find the single most liked subject because a child may say 'yes' to more than one subject.