MathematicsMultiplication & DivisionAges 8–11

Unknown in Multiplication & Division

Determine the unknown whole number in a multiplication or division equation relating three whole numbers (e.g. 8 × ? = 48, ? × 6 = 42)

Lesson

Set out your lesson

Use an inverse relationship to find an unknown quantity.

Before teaching

Use this short check, then start teaching.

Activity

Inferred, not a taxonomy edge: learner can access the supplied prompt with agreed support and can explain or mark a response. If earlier skills are unfamiliar, use the prerequisite topic for teaching; an authored prerequisite is not proof this learner is ready.

Printer, credit, and teaching notes

Sequence

Keep the two adult-only cards off the learner screen. Have a pencil and scrap paper if useful; oral pointing/typing/AAC can replace handwriting unless spelling or composition is the target. No printing, cutting, account or purchase is required.
Open Show first, read the explanation together, and pause to check the central idea. Then do Guided Try together.
For Try, close earlier models and the adult keys unless the task explicitly supplies a reference. Record any hints, read-aloud help or model reopening; do not call supported work independent.
Use only the active learner card. Keep the private key closed until an attempt is recorded. Stop or take a break on request; practical claims stay not observed unless actually done.

No Printer

Use on screen; read aloud or recreate a tactile model only with declared support. No printer or purchased kit.

Privacy

Never display adult keys or dictation spellings with a learner task; no family financial, identity or conflict disclosure.

Use the complete materials on screen or print only the current sheet. Keep adult guidance out of learner view.

Next: Show

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1858 concepts · 9 subjects

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Teaching approaches

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1 approach

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Use an inverse relationship to find an unknown quantity.

Family records and proof options

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

View learner plans ($12/mo per learner) See sample family archive

Learning resources

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

Illustrative Mathematics · Practice link — not the full lesson

Finding the unknown in a division equation

Open practice(new tab)

Before you open · source notes

Learners find the missing number in a division equation. Use it for unknown factors in ÷ equations, not every times-table product.

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 number makes the division equation true and how multiplication could check it.

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 2026-11-11 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. “Finding the unknown in a division equation.” 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

Find the missing factor in 7 × ? = 63
Find the missing dividend in ? ÷ 5 = 9
Explain the strategy used (e.g. using the related multiplication fact)

“If your child sees '8 × ? = 48' or '? ÷ 6 = 7' written on paper, can they figure out what number goes in the blank?”

Curriculum record

Type: Procedural
Subject: Mathematics
Domain: Multiplication & Division
Age range: Ages 8–11

Standards

acara-v9:AC9M5A01acara-v9:AC9M5A02ccss-math:3.OA.4the-ontario-curriculum-mathematics-2020:ON-MATH-2020-G4-C2.2the-ontario-curriculum-mathematics-2020:ON-MATH-2020-G4-E2.6the-ontario-curriculum-mathematics-2020:ON-MATH-2020-G5-C2.3