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
Align two endpoints when comparing lengths; do not infer length from vertical position alone.
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.
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Order three lengths and use a third object as an indirect comparison tool.
Order three lengths and use a third object as an indirect comparison tool.
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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?
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 openAsk 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