Using Simple Formulae
Use simple formulae expressed in words or symbols to calculate values (e.g. perimeter = 2 × (length + width))
Lesson
Set out your lesson
Read a formula, replace each letter with its given value, follow the operation order and state the correct unit.
Before teaching
Use this short check, then start teaching.
Ask for 2 × (6 + 3) and half of 24. Expect 18 and 12. Ask which unit measures a boundary length and which measures area: centimetres and square centimetres. If the distinction is new, teach it before interpreting answers. The geometric formulae are supplied; no formula recall is required.
Check readiness directly. Prerequisite availability is not attainment.
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Read a formula, replace each letter with its given value, follow the operation order and state the correct unit.
Read a formula, replace each letter with its given value, follow the operation order and state the correct unit.
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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
Distance to School
Before you open · source notes
Distance to School supports using a simple formula-style expression for distance. Not every advanced algebra proof.
Free, no sign-in. A teacher solution is on the same page, so use the student view with your child.
Before you openAsk the learner to use the distance relationship and substitute numbers into 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 2026-11-12 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. “Distance to School.” 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
- Substitute values into P = 2(l + w) to find the perimeter of a rectangle
- Use the formula for area of a triangle (A = 1/2 × b × h) given base and height values
- Interpret a formula expressed in words and use it to compute an output
“If your child is told that the perimeter of a rectangle uses the formula perimeter = 2 × (length + width), can they plug in the measurements and work out the answer?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Algebra
- Age range
- Ages 10–13
Standards