# Lesson 103: Comparing weights and volumes

🧮 MATH (40 Lessons) • 🟡 C. Shapes and Measurement

← Back to Level 1

## Objective

I can compare how heavy or light objects are and how much containers can hold. I can use words like heavy, light, heavier, lighter, full, empty, holds more, and holds less. I also hear the unit names grams (g), kilograms (kg), and liters (L).

## Materials

- Light objects: a pencil, small toy, or eraser
- Heavier objects: a book, lunch box, or backpack
- Two or more containers: a small cup and a larger bottle or jug
- Optional: water or dry beans (for demonstrating full and empty safely)

## Mini-lesson — Comparing weights and how much things hold

In this lesson, we compare how heavy things are and how much they can hold. We use real objects that children see every day.

Heavy and light

- Some things are light (like a feather or an empty paper cup).
- Some things are heavy (like a full water bottle or a bag of books).
- We say one object is heavier than or lighter than another object.

Balance scales

- A balance scale has two pans.
- If one side goes down, that side is heavier.
- If one side goes up, that side is lighter.

Full, empty, and how much containers hold

- Containers like cups, bottles, and jugs can be full, half full, or empty.
- We say one container holds more or holds less than another.
- A tall bottle might hold more than a small cup, even if both look full.

Simple units we see in real life

- On food packets, we see g (grams) and kg (kilograms) for weight.
- On drink bottles, we see L (liters) or ml (milliliters) for how much liquid they hold.
- For this level, children just notice these labels and use them to talk about heavier / lighter and holds more / holds less.

In this lesson, focus on comparing two objects at a time: which one is heavier, which one is lighter, and which container holds more or holds less.

Picture strip: Balance scale and containers.

Balance scale — heavy vs light

Containers — full and empty

## Guided Practice — Real objects for weight and how much they hold

You will use real objects from your classroom or home. First, feel which ones are heavier or lighter. Then use the tracing pad to write the most important measurement words.

1. Pick two objects to compare: For example, choose a full water bottle and an empty bottle, or a small cup and a large jug.
2. Feel the weight: Hold one object in each hand. Notice which one feels heavier and which one feels lighter.
3. Think about how much they hold: Look at the shapes and sizes. Decide which container holds more and which holds less.
4. Write the key words: On your paper or notebook, write these words in a list:
   • heavy • light • full • empty • holds more • holds less
5. Look at the labels (if there are any): If your packet or bottle has writing on it, find numbers like 500 g, 1 kg, or 1 L. These are units that tell how much something weighs or how much it holds.
6. Use the tracing pad: Choose two words that match your objects (for example, heavy and light or full and empty) and trace them on the tracing pad.
7. Add a small picture: Next to each word, draw a tiny picture that matches it, such as a full bottle for full or an empty cup for empty.

Tracing Pad
Lines
Trace
Pen

## Practice 1 — Comparing weights

[PLACEHOLDER PRACTICE 1]

## Practice 2 — Comparing volumes (how much a container holds)

[PLACEHOLDER PRACTICE 2]

## Practice 3 — Using the unit names

[PLACEHOLDER PRACTICE 3]

## Quick Check — Comparing weights and volumes

Answer each question about heavy and light, full and empty, and the unit names grams (g), kilograms (kg), and liters (L). You may look back at the mini-lesson.

1) Which object is usually lighter?

A school bag full of books A single pencil A big box of toys
A pencil is a small, light object.

2) Which object is usually heavier?

A paper clip A feather A math textbook
A textbook weighs more than a paper clip or a feather.

3) When we measure how heavy something is, we use units like:

grams (g) and kilograms (kg) minutes and hours centimeters and meters
Grams and kilograms are names of units for weight.

4) When we measure how much liquid a container can hold, we use units like:

grams (g) liters (L) days and weeks
Liters are used for liquids like water, milk, or juice.

5) Which container most likely holds more?

A tiny medicine cup A spoon A big water bottle
A big bottle has room for more liquid than a cup or spoon.

6) Which word means the container has nothing inside?

empty heavy full
Empty means there is nothing inside the container.

7) Which word means the container is filled to the top?

light holds less full
Full means there is no more space inside.

8) A leaf and a stone are on the table. Which one is lighter?

The stone The leaf They weigh the same
A leaf is much lighter than a stone.

9) A full backpack and an empty backpack are on the floor. Which is heavier?

The full backpack The empty backpack They are the same
When we add books, the backpack becomes heavier.

10) Which of these is most likely measured in liters (L)?

A pencil A box of blocks A jug of orange juice
Orange juice is a liquid, so we think about liters.

11) Which of these is most likely measured in kilograms (kg)?

A paper clip A suitcase full of clothes A drop of water
A heavy suitcase is a good example of something measured in kilograms.

12) Which of these is most likely measured in grams (g)?

A small chocolate bar A car A swimming pool
Small, light things like chocolate bars are often measured in grams.

13) Your teacher asks, “Which cup holds less water?” What should you look for?

The tallest cup The cup with the brightest color The smallest cup
A smaller cup can hold less liquid than a large one.

14) Which sentence is true?

An empty bottle is heavier than a full bottle. A full bottle is heavier than an empty bottle. Full and empty always weigh the same.
When we add water, we add weight, so the full bottle is heavier.

15) Why do we learn unit names like grams, kilograms, and liters?

To count our toys To tell the time of day To talk about how heavy things are and how much they can hold
Unit names help us describe weight and volume clearly.

## Assessment (parent/teacher)

Student can compare two objects as heavy or light. Student can use heavier and lighter correctly in sentences. Student can compare containers as holding more or holding less. Student understands full and empty when looking at containers. Student can say that grams (g) and kilograms (kg) are units for weight, and liters (L) are units for liquid.

## Exit ticket (student)

😀 I can compare heavy and light objects easily. 🙂 I can compare some weights and volumes but still need more practice. 😅 Comparing weights and volumes still feels tricky for me.

#### Next time I will practise…

Comparing two objects to see which is heavier or lighter Looking at containers to see which holds more or holds less Saying grams, kilograms, and liters when we talk about measuring
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