What is a Third (Quantity)?

S0-SA1-1359

Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A 'third' of a quantity means dividing that whole quantity into three equal parts. It represents one out of those three equal parts. Think of sharing something equally among three friends.

Simple Example

Quick Example

Imagine you have a delicious gulab jamun. If you cut it into 3 exactly equal pieces, then each piece is one-third of the whole gulab jamun. So, one piece is 1/3 of the gulab jamun.

Worked Example

Step-by-Step

Let's find one-third of 15 laddoos.

Step 1: Understand the total quantity. We have 15 laddoos.
---Step 2: Understand what 'one-third' means. It means dividing the total into 3 equal parts.
---Step 3: Perform the division. Divide 15 by 3.
---Step 4: Calculation: 15 ÷ 3 = 5.
---Answer: One-third of 15 laddoos is 5 laddoos.

Why It Matters

Understanding 'thirds' is fundamental for sharing things fairly and calculating proportions in daily life. From budgeting your pocket money to designing buildings as an architect or managing finances as an accountant, fractions like a third are everywhere. It helps you make sure everyone gets an equal share!

Common Mistakes

MISTAKE: Dividing by 1/3 instead of 3 when finding one-third. | CORRECTION: To find one-third of a number, you should divide the number by 3, not multiply it by 3 or divide it by 1/3.

MISTAKE: Thinking 'one-third' means three times the quantity. | CORRECTION: 'One-third' means a smaller part, specifically one out of three equal parts. It always makes the quantity smaller.

MISTAKE: Not ensuring the parts are equal when visualizing 'one-third'. | CORRECTION: For something to be a 'third', all three parts must be exactly the same size or value.

Practice Questions

Try It Yourself

QUESTION: What is one-third of 21 mangoes? | ANSWER: 7 mangoes

QUESTION: A 30-minute online class is divided into three equal segments. How long is each segment? | ANSWER: 10 minutes

QUESTION: If a family spends one-third of their monthly income of Rs 36,000 on rent, how much do they pay for rent? | ANSWER: Rs 12,000

MCQ

Quick Quiz

Which of the following represents one-third of 18?

18 x 3

18 / 3

18 + 3

18 - 3

The Correct Answer Is:

To find one-third of a number, you divide the number by 3. So, 18 divided by 3 gives one-third of 18. Options A, C, and D perform different operations.

Real World Connection

In the Real World

When you're sharing a pizza with two friends, you usually cut it into three equal slices. Each slice is one-third of the whole pizza. Similarly, chefs often use 'one-third cup' measurements for ingredients when following a recipe to ensure the dish tastes perfect.

Key Vocabulary

Key Terms

FRACTION: A part of a whole. | DIVIDE: To split into equal parts. | EQUAL PARTS: Pieces that are exactly the same size or value. | WHOLE: The entire quantity or amount.

What's Next

What to Learn Next

Great job understanding 'one-third'! Next, you can explore 'one-fourth' and other simple fractions. This will build on your current knowledge and help you understand how to divide things into many more equal parts.