# Lesson 99: Comparing length and height

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

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## Objective

I can compare the length and height of objects. I can use words like longer, shorter, taller, and shorter and explain how I know.

## Materials

- Everyday classroom objects (pencils, crayons, glue sticks, books)
- A flat table or floor space to line up objects
- Pencil and notebook or scrap paper

## Mini-lesson — Longer, shorter, taller, shorter

We use length to talk about how long something is from one end to the other. We use height to talk about how tall something is from bottom to top.

Comparing length

- To compare length, line up objects so their ends match.
- Look at which one sticks out more.
- Say, for example, "The pencil is longer than the crayon".

Comparing height

- To compare height, stand objects on the same surface.
- Look at the tops and see which is higher.
- Say, for example, "The glue stick is taller than the eraser".

Ordering three objects

- Put three pencils in a row with ends lined up.
- Find the shortest and the longest.
- Say the order: "Shortest, middle, longest" or "shorter than" and "longer than".

In this lesson, we do not measure with numbers yet. We just compare and order using length, height, and comparison words.

Picture strip: Comparing classroom objects

Length — pencil and crayon

Height — glue stick and eraser

## Guided Practice — Compare classroom objects

You will compare real objects from your home or classroom. You will use words like longer, shorter, taller, and shorter and then use the tracing pad.

1. Pick two things: Choose a pencil and a crayon. Put them on the table so their ends line up.
2. Compare length: Look to see which one sticks out more. Say a sentence like, "The pencil is longer than the crayon".
3. Swap objects: Try a glue stick and a crayon. Line up the bottom ends. Say, "The glue stick is taller than the crayon".
4. Order three things: Choose three pencils or three books. Line them up and find the shortest and the longest (or tallest).
5. Explain your thinking: Ask the child to explain how they know, using words like length, height, longer, and shorter.
6. Draw it: In the notebook, draw two or three simple objects and use arrows to show which is longer or taller.
7. Use the tracing pad: Pick words such as long, short, tall, or height from the dropdown and trace them slowly. Add a tiny picture for each word.

Tracing Pad
Lines
Trace
Pen

## Practice 1 — Compare length

[PLACEHOLDER PRACTICE 1]

## Practice 2 — Compare height

[PLACEHOLDER PRACTICE 2]

## Practice 3 — Order three objects

[PLACEHOLDER PRACTICE 3]

## Quick Check — Comparing length and height

Answer each question about length, height, and comparison words. You may use real objects to help you think.

1) What does length tell us?

How long something is from end to end. How many colours it has. How heavy it feels.
Length is how long something is from one end to the other.

2) What does height tell us?

How wide something is. How tall something is from bottom to top. How loud something is.
Height is how tall something is from the bottom to the top.

3) Two pencils are lined up at one end. One sticks out more. What can you say?

They are the same length. The one that sticks out is shorter. The one that sticks out is longer.
If it sticks out more, it is longer.

4) Which words help us compare length?

longer, shorter louder, softer heavier, lighter
We use longer and shorter to compare length.

5) Which words help us compare height?

wider, narrower taller, shorter louder, quieter
We use taller and shorter to compare height.

6) A glue stick and an eraser are standing on the table. The glue stick reaches higher. Which sentence is true?

The eraser is taller than the glue stick. They are the same height. The glue stick is taller than the eraser.
The object that reaches higher is taller.

7) Why do we line up objects at one end when we compare?

So the comparison is fair and we can see which really is longer. So we can hide one object. So they all touch the wall.
Lining up ends makes the comparison fair.

8) You have three pencils. Pencil A is the shortest. Pencil C is the longest. Where does Pencil B belong?

It is the shortest. It is in the middle. It is the longest.
If A is shortest and C is longest, B is in the middle.

9) Which sentence is correct?

"The taller object is always shorter." "The shorter object is higher." "The taller object reaches higher than the shorter one."
Taller means it reaches higher than the shorter one.

10) A book and a notebook are lined up along the bottom. The book is higher. What does this tell you?

The book is taller than the notebook. The notebook is taller than the book. They are the same height.
If it is higher when lined up, it is taller.

11) Which question is about length?

"Which is heavier, the ball or the block?" "Which is longer, the ribbon or the string?" "Which is louder, the drum or the bell?"
Asking which is longer is a length question.

12) Which question is about height?

"Which is wider, the desk or the rug?" "Which is longer, the pen or the marker?" "Which tower of blocks is taller?"
Towers of blocks are compared with height.

13) A ruler and a crayon are lined up. The crayon stops before the end of the ruler. Which is true?

The crayon is shorter than the ruler. The crayon is longer than the ruler. They are the same length.
If it ends earlier, it is shorter.

14) Why is it important to compare objects carefully?

So we can guess without looking. So we can tell which is really longer or taller and explain why. So we can hide the shorter object.
Careful comparing helps us explain our thinking clearly.

15) You compare two pencils and say, "This one is longer." What should you do next to show good maths thinking?

Put them away quickly. Change your mind without looking. Explain how you lined them up and how you could see the difference.
Explaining how you compared the objects shows strong maths thinking.

## Assessment (parent/teacher)

Student can explain the difference between length and height in simple words. Student can compare two objects and say which is longer or shorter. Student can compare the height of two objects and say which is taller or shorter. Student can order three objects by length or height (shortest to longest or tallest). Student can explain how they lined up objects to make a fair comparison.

## Exit ticket (student)

😀 I can compare length and height easily. 🙂 I can compare some objects but still need more practice. 😅 Comparing length and height still feels tricky for me.

#### Next time I will practise…

Saying which object is longer or shorter Saying which object is taller or shorter Ordering three objects by length or height
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