Comparing lengths by measuring
Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit
Lesson
Set out your lesson
“Comparing lengths by measuring means practising the idea at the table with counters or paper models and one clear check. We will demo once, then your child tries.”
Bring to the table
- 20 counters
- Paper and pencil
Extra for the adult
Worked example. Start with 12 counters, remove 4, 8 remain. Write 12 − 4 = 8.
Optional challenge. For Comparing lengths by measuring, add one harder example after success.
What to notice. Keep one parent note: examples tried; results; support used. This session samples Comparing lengths by measuring, not mastery.
Share and support
Family records and proof options
Keep a record of your learning
Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.
Practice this concept
Start practiceComparing lengths by measuring practice
Practice key ideas from Comparing lengths by measuring.
Free · no login · no ads · Practice answers and completion are not saved. Parent observation remains the lesson record.
Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
Illustrative Mathematics · Practice link — not the full lesson
Determining Length
Before you open · source notes
Measure two foot outlines in a standard unit and compare the difference. A parent and child can be the pair. The activity requires a ruler or measuring tape.
Free, no sign-in. Use the student view with your child.
Before you openRecord the unit before measuring. Ask which outline is longer and by how many units. The page does not measure or score the outlines.
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 2026-11-10 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. “Determining Length.” 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
- Measure two objects and calculate the difference in length
- Express the difference using the correct unit (e.g. '7 cm longer')
- Solve a comparison problem: 'How much taller is the bookshelf than the desk?'
“If a pencil is 16 cm and a crayon is 9 cm, can your child work out how much longer the pencil is — without measuring them side by side?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Measurement
- Age range
- Ages 7–8
Standards