Addition and subtraction within 1000
Add and subtract within 1000 using concrete models, drawings, and strategies based on place value; understand composing and decomposing tens and hundreds
Lesson
Set out your lesson
“Addition and subtraction within 1000 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 Addition and subtraction within 1000, add one harder example after success.
What to notice. Keep one parent note: examples tried; results; support used. This session samples Addition and subtraction within 1000, 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 practiceAddition and subtraction within 1000 practice
Practice key ideas from Addition and subtraction within 1000.
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
How Many Days Until Summer Vacation?
Before you open · source notes
Subtract 124 from 180 in a fictional school-calendar story. Counting-on and regrouped base-ten models are instructional support, not a fluency certification for addition and subtraction within 1000.
Free, no sign-in. A teacher solution is on the same page, so use the student view with your child.
Before you openA family can discuss the given story without adopting that calendar. Ask how a ten was regrouped, and record the explanation.
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. “How Many Days Until Summer Vacation?.” 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
- Add two three-digit numbers using base-ten blocks or drawings, composing a ten or hundred when necessary
- Subtract three-digit numbers, decomposing a ten or hundred when necessary
- Relate the concrete/drawn strategy to a written method and explain why it works
“Can your child add or subtract numbers in the hundreds — like '347 + 256' — by thinking about hundreds, tens, and ones separately, or drawing a diagram to help?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Addition & Subtraction
- Age range
- Ages 7–9
Standards