Writing Algebraic Equations
Express missing number problems algebraically using letters for unknowns; translate word problems into equations
Lesson
Set out your lesson
Use a letter for an unknown, write a matching equation, solve it with inverse operations and check it in the original situation.
Before teaching
Use this short check, then start teaching.
Ask for an expression for three equal groups of 4 with 2 more added. Expect 3 × 4 + 2. Ask what number added to 6 makes 10. Expect 4. If needed, use an empty box for the unknown before replacing the box with a letter.
Check readiness directly. Prerequisite availability is not attainment.
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.
Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
Illustrative Mathematics · Practice link — not the full lesson
Introducing Equivalent Expressions 1
Before you open · source notes
Introducing Equivalent Expressions 1 supports writing algebraic equations and expressions that match. Not every calculus identity.
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 write an equation or expression that matches a situation and name a variable.
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. “Introducing Equivalent Expressions 1.” 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
- Write 'I think of a number, double it, and add 5 to get 17' as 2n + 5 = 17
- Solve a one-step equation such as 3x = 24 and explain the reasoning
- Express a word problem as an algebraic equation and find the unknown value
“If your child reads "I think of a number, double it, and add 5 to get 17," can they write that as an equation using a letter for the unknown and solve it?”
Curriculum record
- Type
- Representational
- Subject
- Mathematics
- Domain
- Algebra
- Age range
- Ages 10–12
Standards