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MathematicsNumber Representation & Place ValueAges 13–14

Number Sets & Infinity

Appreciate the infinite nature of the sets of integers, real numbers, and rational numbers; position integers on a number line and distinguish between rational and irrational numbers

Lesson

Set out your lesson

“Number Sets & Infinity 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

  • Two colours of counters
  • Paper for ratio or percent notation
Extra for the adult

Worked example. 2 red and 3 blue is the ratio 2:3.

Optional challenge. For Number Sets & Infinity, add one harder example after success.

What to notice. Keep one parent note: examples tried; results; support used. This session samples Number Sets & Infinity, not mastery.

Continue learning
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 practice
Gakuva activity

Number Sets & Infinity practice

Practice key ideas from Number Sets & Infinity.

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.

PhET Interactive Simulations · Practice link — not the full lesson

Number Line: Integers

Open practice (new tab)
Before you open · source notes

Number Line: Integers supports hands-on exploration for Number Sets & Infinity. Not every lab worksheet.

Free interactive page, no sign-in required for the tested path.

Before you open

Ask the learner what they changed in the sim or page and what they observed.

Opening this link does not save learning or assess mastery.

Source, access and review notes

Public PhET Interactive Simulations page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.

PhET Interactive Simulations. “Number Line: Integers.” External page; Gakuva does not copy, host, embed, or redistribute materials.

Unknown — link only

Check understanding

  • Explain that rational numbers can be written as a fraction of two integers and have terminating or repeating decimals
  • Give examples of irrational numbers and explain why their decimal expansions neither terminate nor repeat
  • Appreciate that between any two numbers there are infinitely many other numbers
“Can your child explain that numbers like √2 and π can't be written as exact fractions — and that their decimal expansions go on forever without repeating?”

Curriculum record

Type
Conceptual
Subject
Mathematics
Domain
Number Representation & Place Value
Age range
Ages 13–14

Standards

ccss-math:8.NS.1ccss-math:8.NS.2uk-nc-2013:KS3.Maths.Num.16