CBSE Class 4 Mathematics NCERT Solutions: Unit 7 Jugs and Mugs

Solution: The donkey is mistaken. 500 millilitres is not more than a litre; it is actually less than one litre. It is exactly half a litre. The relationship between millilitres and litres is that 1 litre equals 1000 millilitres. Therefore, 500 millilitres is half of 1000 millilitres, making it half a litre.

Solution: To find the total amount of liquid in ten glasses, each holding 100 ml, we need to multiply the volume of one glass by the number of glasses.

Calculation:

Number of glasses = 10

Volume per glass = 100 ml

Total volume = Number of glasses × Volume per glass

$$10\; \backslash times\; 100\; \backslash text\{\; ml\}\; =\; 1000\; \backslash text\{\; ml\}$$

So, ten glasses of 100 ml each hold a total of 1000 millilitres, which is equal to 1 litre.

Solution: The fox is explaining the calculation for the total volume of 10 glasses, each containing 100 ml.

First, calculate the total volume in millilitres:

10 times hundred millilitres = $10\; \backslash times\; 100\; \backslash text\{\; ml\}$

= $1000\; \backslash text\{\; ml\}$

Next, convert this volume to litres. Since 1000 ml equals 1 litre:

= 1 litre.

So, 10 times hundred millilitres is 1000 millilitres, which is equal to 1 litre.

Solution: The elephant is calculating the total amount of kheer needed for 1000 ants, knowing that each ant consumes 1 millilitre.

To find the total volume, we multiply the number of ants by the amount of kheer each ant drinks:

Number of ants = 1000

Kheer per ant = 1 mL

Total kheer = Number of ants × Kheer per ant

Total kheer = $1000\; \backslash times\; 1\; \backslash text\{\; mL\}$

= $1000\; \backslash text\{\; mL\}$

Since 1000 mL is equal to 1 litre, the 1000 ants will drink 1000 mL or 1 litre of kheer.

Solution: This question asks for a personal estimation of how much kheer a student can consume. The answer is subjective and depends on individual appetite. A common and reasonable answer is provided as an example.

Example Answer: I can have only 200 ml of kheer.

Solution: This question probes the student's understanding of large liquid volumes in relation to human consumption. Drinking 1 litre (which is 1000 ml) of water at once is a significant amount for most people, especially children.

Answer: No. I cannot drink 1 L water at one time.

Solution: The goal is to find combinations of volumes that add up to 1 litre (1000 mL). Let's complete the chart by finding the missing values or verifying the sums provided.

Example Combinations to make 1000 mL:

• 400 mL + 600 mL = 1000 mL (1 Litre)
• 300 mL + 700 mL = 1000 mL (1 Litre)
• 250 mL + 750 mL = 1000 mL (1 Litre)
• 800 mL + 200 mL = 1000 mL (1 Litre)
• 500 mL + 500 mL = 1000 mL (1 Litre)
• 300 mL + 300 mL + 400 mL = 1000 mL (1 Litre)
• 300 mL + 400 mL + 300 mL = 1000 mL (1 Litre)
• 100 mL + 300 mL + 600 mL = 1000 mL (1 Litre)

The chart requires filling in the missing numbers or confirming that the given numbers add up to 1000 mL.

Solution: This exercise encourages students to observe their surroundings and identify different products that come in measured quantities. Here is a sample list based on common household items:

List of Items in Packets or Bottles:

Packet/Bottle Contents	How many mL or L?
Milk	500 mL (or 1 L carton)
Cold drink/Soft drink	1000 mL or 1 L (bottle/can)
Kissan drink (Juice)	500 mL (pouch/bottle)
Tomato sauce/Ketchup	970 mL (bottle)
Eye drops	$5\; \backslash text\{\; mL\}$ (small bottle)
Cough syrup	100 mL (bottle)
Glue	100 mL (tube/bottle)
Hand sanitizer	200 mL (bottle)
Cooking oil	1 L (pouch/bottle)

Students should fill this list with items they find at home or in a store.

Solution: This is a simple observational question to connect the concept of a litre to a common real-world object. Many people have seen or used one-litre water bottles.

Answer: Yes. I have seen water bottles that hold one litre.

Solution: This question requires students to perform an activity, likely involving estimation and then measurement. The 'table' mentioned is not provided in the source text, but the process involves:

1. Guessing: Estimating the volume of different containers (e.g., a jug, a mug, a bowl) in millilitres or litres.
2. Checking: Using a known measure (like a 1-litre bottle or a measuring jug) to pour liquid into the container and see how much it holds, or pouring the contents of the container into the measuring device.
3. Filling the Table: Recording the guessed volume and the actual measured volume for each container.

For example, a student might guess a jug holds 500 mL, then use a 1-litre bottle to find out it actually holds 750 mL.