Sharing and Measuring — Class 4 Mathematics (CBSE)

From the current NCERT Maths Mela Grade 4 book, Chapter 5. Sharing a dosa, a chapati, or a garden fairly leads us to fractions.

1. Why this chapter matters

When we share something fairly, everyone gets an equal part. These equal parts are fractions — halves and quarters — which we use to cut food, measure, and tell time. Sharing also shows that the more people share, the smaller each part becomes.

2. Core ideas

Idea 1 — A fraction names equal parts of a whole

One of two equal parts is one-half (½). One of four equal parts is one-quarter (¼).

Method 2 — Equal sharing makes fractions

To share a dosa between 2, fold/cut it into 2 equal parts — each gets ½. Among 4, each gets ¼.

Skill 3 — More sharers, smaller share

As more people share the same whole, each part gets smaller: ½ is bigger than ¼.

3. Worked examples

Example 1: A roti is shared equally between 2 children. What part does each get?

Each gets one-half (½).

Example 2: A cake is cut into 4 equal pieces. What is each piece?

Each piece is one-quarter (¼).

Example 3: Which is bigger, ½ or ¼ of the same dosa?

½ is bigger — sharing into 2 parts gives larger pieces than into 4.

4. Activity corner

Fold a paper "dosa" into halves, then into quarters. Colour one-half on one paper and one-quarter on another. Write:

• How many equal parts you folded
• The fraction name of one part
• The maths idea (equal parts = fractions)

5. Common mistakes

• Mistake: Calling unequal parts halves. Fix: Halves and quarters must be equal parts.
• Mistake: Thinking ¼ is bigger than ½ because 4 is bigger than 2. Fix: Of the same whole, ½ is bigger than ¼.
• Mistake: Forgetting the parts rejoin to a whole. Fix: Two halves, or four quarters, make one whole.

6. How to write better answers

1. Check the parts are equal.
2. Name the fraction: half (½) or quarter (¼).
3. To compare, remember more parts means smaller pieces.
4. Show your folding or sharing clearly.

7. Practice set

1. What do we call one of two equal parts?
2. Write the fraction for one-quarter.
3. A garden is shared equally among 4 friends. What part does each get?
4. Which is bigger: ½ or ¼ of the same chapati?
5. How many quarters make one whole?
6. Half of 12 sweets is how many?

8. Answer key

1. One-half (½).
2. ¼.
3. One-quarter (¼).
4. ½ is bigger.
5. 4 quarters.
6. 6 sweets.

9. Quick revision

• A fraction names equal parts of a whole.
• One-half = ½ (1 of 2 equal parts); one-quarter = ¼ (1 of 4 equal parts).
• More sharers means a smaller share; ½ > ¼ of the same whole.
• Two halves, or four quarters, make one whole.
• Half of a number shares it into 2 equal groups.