What is 1/3 (One Third)?

S1-SA2-0205

Grade Level:

Class 2

Maths, Chemistry, Physics

Definition

What is it?

One-third (written as 1/3) means dividing something into three equal parts and taking just one of those parts. It represents one portion out of a total of three equal portions.

Simple Example

Quick Example

Imagine you have a delicious gulab jamun. If you cut it into three pieces that are exactly the same size, and you eat one of those pieces, you have eaten one-third (1/3) of the gulab jamun.

Worked Example

Step-by-Step

Let's find one-third of 15 laddoos.

Step 1: Understand the question. We need to divide 15 laddoos into 3 equal groups.
---
Step 2: To find one-third, we divide the total number by 3.
---
Step 3: Calculation: 15 / 3
---
Step 4: Perform the division. 15 divided by 3 is 5.
---
Answer: One-third of 15 laddoos is 5 laddoos.

Why It Matters

Understanding fractions like one-third is fundamental in Maths for concepts like ratios and percentages. In Chemistry, you might use it to understand parts of a solution. In Physics, it helps when dealing with forces or measurements. Engineers and scientists use fractions daily to design things, mix chemicals, or calculate forces.

Common Mistakes

MISTAKE: Thinking 1/3 means taking 1 part out of 3 unequal parts. | CORRECTION: 1/3 always means 1 part out of 3 *equal* parts. The 'equal' part is very important.

MISTAKE: Confusing 1/3 with 1 divided by 3, but not understanding what the '3' means. | CORRECTION: The '3' in 1/3 tells you the total number of equal parts the whole is divided into.

MISTAKE: Believing 1/3 of a number is always a whole number. | CORRECTION: 1/3 of a number can be a fraction or a decimal if the number is not perfectly divisible by 3 (e.g., 1/3 of 10 is 3.33...).

Practice Questions

Try It Yourself

QUESTION: Your mom made a dosa and cut it into 3 equal pieces. If you eat one piece, what fraction of the dosa did you eat? | ANSWER: 1/3

QUESTION: There are 21 students in a class. If one-third of the students are girls, how many girls are there? | ANSWER: 7 girls (21 / 3 = 7)

QUESTION: A recipe needs 2 cups of milk. If you want to make only one-third of the recipe, how much milk do you need? Express your answer as a fraction. | ANSWER: 2/3 cup of milk (1/3 of 2 is 2/3)

MCQ

Quick Quiz

Which of these represents one-third of the total amount?

Dividing a cake into 2 pieces and taking 1

Dividing a pizza into 3 equal slices and taking 1

Dividing a chocolate bar into 4 pieces and taking 1

Taking 3 pieces from a total of 10 pieces

The Correct Answer Is:

Option B correctly describes one-third: dividing something into 3 *equal* parts and taking 1. The other options involve different numbers of parts or unequal divisions.

Real World Connection

In the Real World

When you are sharing a large pack of biscuits equally among three friends, each friend gets one-third of the biscuits. Or if a tailor needs to cut a 3-meter cloth into three equal parts for kurta sleeves, each sleeve will use one-third of the cloth, which is 1 meter.

Key Vocabulary

Key Terms

FRACTION: A part of a whole. | NUMERATOR: The top number in a fraction, showing how many parts you have. | DENOMINATOR: The bottom number in a fraction, showing how many total equal parts there are. | EQUAL PARTS: Pieces that are exactly the same size.

What's Next

What to Learn Next

Now that you understand one-third, you can explore other unit fractions like one-half (1/2) and one-fourth (1/4). You'll see how fractions help us describe parts of things in a precise way.