Weigh it, Pour it

Note: The actual pictures of animals are not visible in the OCR. However, the approach is as follows:

Given: Pictures of different animals.

Concept: We compare animals by their known weights. Generally, larger animals are heavier.

Example order (if the animals shown are elephant, tiger, dog, cat, sparrow):

Heaviest to Lightest:
1. Elephant
2. Tiger
3. Dog
4. Cat
5. Sparrow

*(Write the names based on the actual animals shown in your textbook picture, arranging from the heaviest to the lightest.)*

Answer (sample): The heaviest object in my home is the refrigerator.

How I knew: I tried to lift or move it and it was very difficult to move even a little. Also, my parents told me it weighs about 50–70 kg. We can also check by looking at the product label or manual which mentions the weight.

Answer (sample): I carry my school bag with some effort because it has many books, notebooks, a water bottle, and a lunch box. It feels heavy on my shoulders.

*(Students should answer based on their own experience.)*

Answer (sample): The heaviest book in my bag is my Mathematics textbook.

How I knew: I picked up each book one by one and compared their weight by holding them in my hands. The Mathematics book felt the heaviest. I could also compare by placing them on a weighing balance.

Answer (sample): My weight is 28 kg.

How I knew: I stood on a weighing machine (bathroom scale) at home and read the number shown on the dial/display. The doctor also measures my weight during health check-ups.

Given: A full pumpkin is shown being weighed.

Concept: If a whole pumpkin weighs, say, $1\ \text{kg}$, then half the pumpkin will weigh half of that.

$$\text{Weight of half pumpkin} = \frac{\text{Weight of full pumpkin}}{2}$$

Answer: The weight of the half pumpkin will be half the weight of the full pumpkin.

*(Write the actual number based on what the full pumpkin weighs in your textbook picture. For example, if the full pumpkin weighs 2 kg, then the half pumpkin weighs 1 kg.)*

Concept: We estimate weight based on our experience and then verify using a weighing balance.

Sample Estimation Table:

| Fruits and Vegetables | Estimation | |
|---|---|---|
| | Less than 1 kg | More than 1 kg |
| 6 Bananas | ✓ | |
| 5 Potatoes | ✓ | |
| 10 Tomatoes | ✓ | |
| 15 Onions | | ✓ |

Reasoning:
- 6 Bananas: Each banana weighs about 100–120 g, so 6 bananas ≈ 600–720 g → Less than 1 kg
- 5 Potatoes: Each potato weighs about 100–150 g, so 5 potatoes ≈ 500–750 g → Less than 1 kg
- 10 Tomatoes: Each tomato weighs about 80–100 g, so 10 tomatoes ≈ 800 g–1 kg → Less than 1 kg (approximately)
- 15 Onions: Each onion weighs about 80–100 g, so 15 onions ≈ 1200–1500 g → More than 1 kg

*(Students should verify by actually weighing these items on a balance.)*

Given: 2 packets of 500 g = 1000 g = 1 kg

Step 1: $2 \times 500\ \text{g} = 1000\ \text{g} = 1\ \text{kg}$

Step 2: Therefore, 1 packet of 500 g $= \dfrac{1}{2}\ \text{kg}$

$$\boxed{500\ \text{g} = \frac{1}{2}\ \text{kg}}$$

Given: One pan has a 500 g daal packet. We need to find how many 250 g packets balance it.

Step 1: $250\ \text{g} + 250\ \text{g} = 500\ \text{g}$

Step 2: So 2 packets of 250 g will balance one 500 g packet.

Step 3: $250\ \text{g} = \dfrac{1}{2}\ \text{of}\ 500\ \text{g}$

$$\boxed{250\ \text{g} = \frac{1}{2}\ \text{of}\ 500\ \text{g}}$$

*(Draw 2 packets of 250 g on the empty pan of the balance.)*

Concept: The pan with the greater weight will tilt downward. If both sides are equal, the balance stays level.

Note: The actual weights on each pan are shown in pictures not visible in the OCR. The general rule to apply is:

- Compare the total weight on the left pan and the right pan.
- The arrow points downward toward the heavier side.
- If both sides are equal, the balance is level (horizontal).

General Method:

(a) Add up all weights on the left pan. Add up all weights on the right pan. Arrow points to the heavier side.

(b) Same method as (a).

(c) Same method as (a).

(d) Same method as (a).

*(Students should look at the weights shown in the pictures in their textbook and draw the arrow toward the heavier pan.)*

Concept: We use grams (g) for lighter objects and kilograms (kg) for heavier objects.

Note: The actual images are not visible. General matching guide:

| Object | Appropriate Unit |
|---|---|
| A feather / leaf / coin | Grams (g) |
| A pencil / eraser / biscuit | Grams (g) |
| A bag of rice / a person / a watermelon | Kilograms (kg) |
| A truck / a car / an elephant | Kilograms (kg) |

*(Match based on the actual objects shown in your textbook picture using the above logic.)*

Given: From the picture, 1 eraser weighs approximately 10 g.

Step 1: Weight of Haldi packet $= 50\ \text{g}$

Step 2: Number of erasers $= \dfrac{50}{10} = 5$

$$\boxed{5\ \text{erasers will weigh the same as a 50 g Haldi packet.}}$$

Given: 1 eraser weighs approximately 10 g; soap bar weighs 100 g.

Step: Number of erasers $= \dfrac{100}{10} = 10$

$$\boxed{A\ 100\ \text{g soap bar will weigh the same as}\ \mathbf{10}\ \text{erasers.}}$$

Given: 1 eraser weighs approximately 10 g; sugar weighs 250 g.

Step: Number of erasers $= \dfrac{250}{10} = 25$

$$\boxed{25\ \text{erasers will weigh the same as 250 g sugar.}}$$

Given: Total Kaju-katli = 1 kg = 1000 g

Concept: Number of boxes $= \dfrac{\text{Total weight}}{\text{Weight of each box}}$

(1) 500 g boxes:
$$\text{Number of boxes} = \frac{1000\ \text{g}}{500\ \text{g}} = \mathbf{2}\ \text{boxes}$$

(2) 250 g boxes:
$$\text{Number of boxes} = \frac{1000\ \text{g}}{250\ \text{g}} = \mathbf{4}\ \text{boxes}$$

(3) 100 g boxes:
$$\text{Number of boxes} = \frac{1000\ \text{g}}{100\ \text{g}} = \mathbf{10}\ \text{boxes}$$

(4) 50 g boxes:
$$\text{Number of boxes} = \frac{1000\ \text{g}}{50\ \text{g}} = \mathbf{20}\ \text{boxes}$$

Answer (sample — students should fill in their own data):

| Items | Weight (per month) |
|---|---|
| Atta | 10 kg |
| Rice | 5 kg |
| Pulses | 2 kg |
| Sugar | 2 kg |

*(Ask your parents at home and fill in the actual quantities used in your family each month.)*

Answer (sample):

1. A book — approximately 500 g
2. A water bottle (empty) — approximately 100 g
3. A pencil box — approximately 300 g

*(Students should write objects they can actually lift easily and estimate their weights.)*

Answer (sample):

1. A bag of rice — approximately 10 kg
2. A bucket full of water — approximately 10–15 kg
3. A suitcase full of clothes — approximately 8–10 kg

*(Students should write objects that require effort to lift and estimate their weights.)*

Concept: Number of 1 kg packets $= \dfrac{\text{Total weight in kg}}{1\ \text{kg}}$

(a) 10 kg:
$$\frac{10\ \text{kg}}{1\ \text{kg}} = \mathbf{10}\ \text{packets}$$

(b) 20 kg:
$$\frac{20\ \text{kg}}{1\ \text{kg}} = \mathbf{20}\ \text{packets}$$

(c) 50 kg:
$$\frac{50\ \text{kg}}{1\ \text{kg}} = \mathbf{50}\ \text{packets}$$

(d) 25 kg:
$$\frac{25\ \text{kg}}{1\ \text{kg}} = \mathbf{25}\ \text{packets}$$

Concept: We match each object with its realistic estimated weight.

Correct Matching:

| Object | Estimated Weight |
|---|---|
| A leaf | 1 g to 5 g |
| A pen | 10 g to 15 g |
| A 1 litre filled bottle | 800 g to 1000 g |
| A cat | 3 kg to 5 kg |
| A wooden chair | 6 kg to 10 kg |
| An empty gas cylinder | 15 kg |
| A tiger | 150 kg to 300 kg |
| An elephant | More than 1000 kg |

Reasoning:
- A leaf is very light → 1 g to 5 g
- A pen is light → 10 g to 15 g
- A filled 1 litre bottle → about 1 kg (800 g–1000 g)
- A cat → 3 kg to 5 kg
- A wooden chair → 6 kg to 10 kg
- An empty gas cylinder → about 15 kg
- A tiger → 150 kg to 300 kg
- An elephant → more than 1000 kg

Answer (sample):

| Less than 1 litre | 1 litre | More than 1 litre |
|---|---|---|
| A glass (250 ml) | A water bottle (1 l) | A jug (2 l) |
| A small cup (100 ml) | A juice carton (1 l) | A bucket (10 l) |
| A teacup (150 ml) | A milk packet (1 l) | A large pot (5 l) |

*(Students should look around their home and write the names of actual containers they find.)*

Given: Capacity of 1 bottle = 500 ml; Capacity of large bottle = 1 l = 1000 ml

Step 1: $500\ \text{ml} + 500\ \text{ml} = 1000\ \text{ml} = 1\ \text{l}$

Step 2: Number of 500 ml bottles $= \dfrac{1000}{500} = 2$

$$\boxed{2\ \text{bottles of 500 ml will fill a 1 l bottle.}}$$

Also: $500\ \text{ml} = \dfrac{1}{2}\ \text{l}$

Given: Capacity of 1 bottle = 250 ml; Capacity of large bottle = 1 l = 1000 ml

Step 1: $250 + 250 + 250 + 250 = 1000\ \text{ml} = 1\ \text{l}$

Step 2: Number of 250 ml bottles $= \dfrac{1000}{250} = 4$

$$\boxed{4\ \text{bottles of 250 ml will fill a 1 l bottle.}}$$

Also: $250\ \text{ml} = \dfrac{1}{4}\ \text{l}$

Given: Capacity of 1 bottle = 100 ml; Capacity of large bottle = 1 l = 1000 ml

Step: Number of 100 ml bottles $= \dfrac{1000}{100} = 10$

$$100 \times 10 = 1000\ \text{ml} = 1\ \text{l}$$

$$\boxed{10\ \text{bottles of 100 ml will fill a 1 l bottle.}}$$

Given: $1\ \text{l} = 1000\ \text{ml}$, so $\dfrac{1}{2}\ \text{l} = 500\ \text{ml}$

(i) 250 ml in $\frac{1}{2}$ l (= 500 ml):
$$\frac{500}{250} = \mathbf{2}$$

(ii) 250 ml in 750 ml:
$$\frac{750}{250} = \mathbf{3}$$

(iii) 100 ml in $\frac{1}{2}$ l (= 500 ml):
$$\frac{500}{100} = \mathbf{5}$$

(iv) 100 ml in 800 ml:
$$\frac{800}{100} = \mathbf{8}$$

Concept: Number of 10 ml cups $= \dfrac{\text{Total capacity}}{10\ \text{ml}}$

10 ml to fill 100 ml bottle:
$$\frac{100}{10} = \mathbf{10}\ \text{cups}$$

(a) 10 ml to fill 250 ml glass:
$$\frac{250}{10} = \mathbf{25}\ \text{cups}$$

(b) 10 ml to fill 500 ml vessel:
$$\frac{500}{10} = \mathbf{50}\ \text{cups}$$

(c) 10 ml to fill 1 l (= 1000 ml) bottle:
$$\frac{1000}{10} = \mathbf{100}\ \text{cups}$$

(a) 1 ml droppers to fill a 10 ml dosing cup:
$$\frac{10\ \text{ml}}{1\ \text{ml}} = \mathbf{10}\ \text{droppers}$$

(b) 1 ml droppers to fill a teaspoon:

A standard teaspoon holds approximately 5 ml.
$$\frac{5\ \text{ml}}{1\ \text{ml}} = \mathbf{5}\ \text{droppers}$$

*(Students should verify by actually using a dropper and a teaspoon.)*

(a) Eye drops: Less than 1 ml at a time (just 1–2 drops, each drop is about 0.05 ml).

(b) Honey: About 5–10 ml (1–2 teaspoons) at a time.

(c) Cough Syrup: About 5–10 ml (1–2 teaspoons) at a time, as prescribed by the doctor.

(d) Cooking Oil: About 10–30 ml (1–3 tablespoons) at a time for cooking one dish.

*(Students should check the labels on bottles at home and discuss with parents.)*

Given: Total oil = 1 l = 1000 ml

Concept: Number of bottles $= \dfrac{1000\ \text{ml}}{\text{size of each bottle}}$

(a) Ms Shetty — 500 ml bottles:
$$\frac{1000}{500} = \mathbf{2}\ \text{bottles}$$

(b) Mr Muthukumar — 200 ml bottles:
$$\frac{1000}{200} = \mathbf{5}\ \text{bottles}$$

(c) Ms Naini — 100 ml bottles:
$$\frac{1000}{100} = \mathbf{10}\ \text{bottles}$$

(d) Ms Kannan — 50 ml bottles:
$$\frac{1000}{50} = \mathbf{20}\ \text{bottles}$$

Answer (sample — students should measure and fill in their own data):

| Container | Estimate | Actual Capacity |
|---|---|---|
| Water bottle | 500 ml | 500 ml |
| Glass | 200 ml | 250 ml |
| Mug | 300 ml | 350 ml |
| Jug | 1 l | 1.5 l |
| Bucket | 10 l | 12 l |
| Teaspoon | 5 ml | 5 ml |
| Bowl | 300 ml | 400 ml |

*(Students should use the bottles collected — 500 ml, 250 ml, 100 ml, 50 ml, 10 ml — to measure and fill in the actual capacities.)*

Answer (sample):

| 50 ml | 100 ml | 200 ml | 250 ml | 500 ml | 900 ml |
|---|---|---|---|---|---|
| Perfume | Eye drops bottle | Juice pack | Milk packet | Cold drink bottle | Juice bottle |
| Nail polish | Cough syrup | Coconut oil | Lassi packet | Cooking oil | |
| Sanitizer | Ear drops | Shampoo sachet | Buttermilk | Shampoo bottle | |

*(Students should visit shops near their home and write the actual items they find in each category.)*

(a) Water I drink in a day:
I drink about 6–8 glasses of water per day. Each glass holds about 250 ml.
$$6 \times 250\ \text{ml} = 1500\ \text{ml} = 1.5\ \text{l}$$
I found out by counting the number of glasses I drink each day.

(b) Water a crow can drink at a time:
A crow can drink about 5–10 ml of water at a time (a few sips).

(c) Milk I drink in one day:
I drink about 1–2 glasses of milk per day.
$$1\ \text{glass} \approx 200\ \text{ml}$$
So I drink about 200–400 ml of milk per day.

(d) Water an elephant drinks in a day:
An elephant drinks about 100–200 litres of water in a day. This is a very large amount because elephants are very big animals.

(a) Water for taking a shower:
About 50–100 litres of water is used for a shower.

(b) Watering crops in a field:
A large amount — about thousands of litres per day depending on the size of the field. For example, 1 hectare of crop may need about 5,000–10,000 litres per day.

(c) Watering flowering plants:
About 1–5 litres per plant per day, depending on the size of the plant.

(d) Washing clothes:
About 30–60 litres for washing a full load of clothes by hand; a washing machine uses about 50–100 litres per wash.

*(These are approximate values. Students should discuss with their family and compare.)*

Activity:

Step 1: Place a container under the leaking tap for 1 hour.

Step 2 (Sample observation): Suppose the container collects 100 ml in 1 hour.

Water lost in 1 hour: $100\ \text{ml}$

Water lost in 1 day (24 hours):
$$100\ \text{ml} \times 24 = 2400\ \text{ml} = 2.4\ \text{l}$$

Water lost in 1 week (7 days):
$$2.4\ \text{l} \times 7 = 16.8\ \text{l}$$

Conclusion: Even a slow drip wastes a large amount of water over time. This shows how important it is to fix leaking taps immediately to conserve water. Water is precious and we must not waste it.