MathematicsMeasurementAges 6–7

Measuring length

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

Lesson

Set out your lesson

Order three lengths and use a third object as an indirect comparison tool.

Before teaching

Activity

Align two endpoints when comparing lengths; do not infer length from vertical position alone.

Policy

Directed source edges are preserved, not assumed completed. If the readiness probe is difficult, model with support and record supported practice instead of independent evidence.

Printer, credit, and teaching notes

Materials

Use the supplied stage-specific structured materials. Three paper strips and a non-stretch string/paper strip long enough to transfer a real object's height. Optional actual objects; supplied length-comparison.svg supports diagram reasoning.

Order

Show, guided, put teaching sheet aside, then task sheets in order; adult keys remain private.

Access

No printing or cutting is required unless explicitly choosing a physical construction. Exact paper alternatives are in each material; adaptations change the evidence mode as stated.

Materials are ready in each step. Use them on screen or print just the current step. Put teaching examples aside before the learner tries.

Next: Show

Adult extras

What this lesson covers and its limits

These are bounded opportunities, not learner attainment. Partial and blocked source requirements remain so.

partial: Order three objects by length and compare the lengths of two objects indirectly using a third object
Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed. This is a bounded task opportunity, not established attainment or automatic use across contexts.
partial: Put three ribbons in order from shortest to longest
Mapped task(s) offer this clause only within the supplied examples. Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed. No attainment or automatic/general performance is claimed.
partial: Use a piece of string to compare the heights of two objects that cannot be placed side by side
Mapped task(s) offer this clause only within the supplied examples. Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed. No attainment or automatic/general performance is claimed.
partial: Explain that if A is longer than B and B is longer than C, then A is longer than C
Mapped task(s) offer this clause only within the supplied examples. Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed. No attainment or automatic/general performance is claimed.
partial: If {{name}} has three pencils of different lengths but can only compare two at a time, can they figure out which is longest — by using a third pencil as a go-between?
Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed. This is a bounded task opportunity, not established attainment or automatic use across contexts.

Real indirect comparison conditional. Source pencil/ribbon variations sampled through diagrams and one optional observation, not claimed as completed.

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Order three lengths and use a third object as an indirect comparison tool.

Family records and proof options

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Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.

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Learning resources

Extra practice links — they do not replace Gakuva’s teaching approach.

Illustrative Mathematics · Practice link — not the full lesson

How Long?

Open practice(new tab)

Before you open · source notes

Classroom objects are measured with length units and compared. This supports measuring length, not every time or mass skill.

Free, no sign-in. A teacher solution is on the same page, so use the student view with your child.

Before you open

Ask which object is longer after measuring with the same unit. One comparison does not cover every unit type.

Opening this link does not save learning or assess mastery.

Source, access and review notes

Public Illustrative Mathematics task page. The .html address responds HTTP 308 to this URL. An anonymous GET of this URL on 2026-11-12 returned HTTP 200 with no login or payment prompt. Where a teacher solution is present, it is on the same page as the student task; this check did not find a separate locked student view. An adult can use the student view section and should not read a solution aloud. Advertising was not observed in the fetched HTML text; that is not a browser, device, or ad-free guarantee. This is a paper or discussion task, not an automatically marked interactive game. Opening the link does not save practice or assess mastery. Diagrams on the page use missing or filename-only alt text, so they are not an accessible image equivalent. Accessibility still depends on an adult describing the picture.

Illustrative Mathematics. “How Long?.” Licensed CC BY-NC-SA 4.0. External task; Gakuva does not copy, host, embed, or redistribute it.

CC BY-NC-SA 4.0 — link only

Check understanding

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

“If your child has three pencils of different lengths but can only compare two at a time, can they figure out which is longest — by using a third pencil as a go-between?”

Curriculum record

Type: Procedural
Subject: Mathematics
Domain: Measurement
Age range: Ages 6–7

Standards

acara-v9:AC9M1M01ccss-math:1.MD.1the-ontario-curriculum-mathematics-2020:ON-MATH-2020-G1-E2.2