---
title: "Ordering and Comparing Lengths"
description: "Order three objects by length and compare the lengths of two objects indirectly using a third object"
canonical: https://lightmysky.com/learn/mathematics/ordering-and-comparing-lengths-mt_skYly2Qm01
source: https://lightmysky.com/learn/mathematics/ordering-and-comparing-lengths-mt_skYly2Qm01.md
retrieved: 2026-09-12
---

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# Ordering and Comparing Lengths

Order three objects by length and compare the lengths of two objects indirectly using a third object

Subject: Mathematics · Area: Measurement · Ages 6 to 7
Page: https://lightmysky.com/learn/mathematics/ordering-and-comparing-lengths-mt_skYly2Qm01

## Ready when they can

- Put three ribbons in order from shortest to longest
- Use a piece of string to compare the heights of two objects that cannot be placed side by side
- Explain that if A is longer than B and B is longer than C, then A is longer than C

## Lesson: Ordering and comparing lengths

You already know how to tell if one thing is longer than another. Now you will learn two new tricks: putting three things in order, and comparing two things that cannot sit side by side.

*(drawing: Look at the three strings. Which one is shortest? Which one is longest?)*

**Example.** Mia has three pencils. She lines up the red pencil next to the blue pencil and sees the red one is shorter. Then she lines up the blue pencil next to the green pencil and sees the blue one is shorter too. So the order from shortest to longest is red, blue, green.

**Tip.** Here is a shortcut: if one thing is longer than a second thing, and that second thing is longer than a third thing, then the first thing is longer than the third one too. You do not need to compare the first and the third directly.

**Recap.** To order things, compare them two at a time. And remember, if A is longer than B, and B is longer than C, then A is longer than C too.

## Practice

18 questions on this page, each with its working shown.

## Needs first

- [Comparing Lengths & Heights](https://lightmysky.com/learn/mathematics/comparing-lengths-and-heights-mt_uhuxX8sg9f)

## Opens up

- [Measuring length (age 6+)](https://lightmysky.com/learn/mathematics/measuring-length-age-6-mt_cqSf213hSa)
- [Comparing lengths by measuring](https://lightmysky.com/learn/mathematics/comparing-lengths-by-measuring-mt_xWg0lI_gG4)