Jugs and Mugs Class 3 NCERT Chapter 11 Guide

What is Capacity?

Capacity is the word we use to describe how much liquid a container can hold. Imagine you have a tiny spoon and a big bucket. If you pour water into both, the bucket can hold a lot more water than the spoon! That means the bucket has a larger capacity. In our daily lives, we measure liquids using two main units: Litre (L) and Millilitre (mL). We use Millilitres (mL) for very small amounts of liquid, like drops of medicine, a cup of tea, or a small carton of juice. We use Litres (L) for larger quantities, like the water in a swimming pool, a bucket, or a big bottle of cola. Remembering the difference helps us estimate how much liquid we need every day!

Important Units and Terms to Remember

Capacity

The maximum amount of liquid that a container can hold.

Litre (L)

The standard unit used to measure larger quantities of liquid. 1 Litre is written as 1 L.

Millilitre (mL)

The unit used to measure smaller quantities of liquid. 1 Millilitre is written as 1 mL.

Conversion Formula

1 Litre (L) = 1000 Millilitres (mL).

How to Measure and Compare Capacities

1. Step 1: Check the Container Size — Look at the container. Is it small like a medicine cup, or large like a water tank?
2. Step 2: Choose the Correct Unit — Use Millilitres (mL) for small containers and Litres (L) for big ones.
3. Step 3: Estimate or Measure — Estimate how many standard cups or mugs of water are needed to fill it up completely.
4. Step 4: Use the Conversion Rule — Remember that 1 Litre equals exactly 1000 mL when adding or subtracting capacities.

Worked Examples with Explanations

• Example 1: How many 250 mL cups of milk are needed to fill a 1-litre jug? Step 1: We know that 1 Litre = 1000 mL. Step 2: Add 250 mL repeatedly until you reach 1000 mL. 250 mL + 250 mL = 500 mL (2 cups) 500 mL + 250 mL = 750 mL (3 cups) 750 mL + 250 mL = 1000 mL (4 cups) Therefore, 4 cups of 250 mL make 1 Litre.
• Example 2: A bucket has 5 Litres of water. Meena adds 3 Litres more. What is the total water in the bucket? Step 1: Identify the unit. Both quantities are in Litres (L). Step 2: Add the numbers directly: 5 L + 3 L = 8 L. Therefore, the total volume of water is 8 Litres.

Exam Tip: Don't Mix Units!

A very common mistake in exams is adding Litres directly to Millilitres. For example, 2 L + 50 mL is NOT equal to 52 L or 52 mL! Always convert them into the same unit before performing addition or subtraction. Convert the litres to millilitres first: 2 L = 2000 mL. Then add: 2000 mL + 50 mL = 2050 mL. Write down your unit symbols (L and mL) clearly in every step to secure full marks!

Practice Questions with Solutions

• Q: A small mug can hold 500 mL of water. How many such mugs are needed to fill a 2 L bottle? A: Step 1: Convert Litres to Millilitres. We know 1 L = 1000 mL. So, 2 L = 2 x 1000 = 2000 mL. Step 2: Divide the total bottle capacity by the mug capacity. 2000 mL ÷ 500 mL = 4. Final answer: 4 mugs of water are needed to fill the bottle.
• Q: Rohan drank 200 mL of juice in the morning and 350 mL of juice in the evening. How much juice did he drink in total? A: Step 1: Write down the volumes. Morning juice = 200 mL. Evening juice = 350 mL. Step 2: Since both units are in mL, add them together. 200 mL + 350 mL = 550 mL. Final answer: Rohan drank 550 mL of juice in total.
• Q: A bucket holds 12 Litres of water. Mother used 5 Litres of water for washing clothes. How much water is left in the bucket? A: Step 1: Identify the total capacity and the amount used. Total water = 12 L. Water used = 5 L. Step 2: Subtract the used water from the total water. 12 L - 5 L = 7 L. Final answer: 7 Litres of water is left in the bucket.
• Q: A bottle contains 1 Litre of water. Sonu drinks 600 mL of it. How much water is left in the bottle? A: Step 1: Convert 1 Litre of water into millilitres. 1 L = 1000 mL. Step 2: Subtract Sonu's portion from the total volume. 1000 mL - 600 mL = 400 mL. Final answer: 400 mL of water is left in the bottle.

Frequently Asked Questions