Adding and subtracting (age 10+)
Solve addition and subtraction multi-step problems in contexts, deciding which operations and methods to use and why, with numbers up to 10,000,000 and decimals
Lesson
Set out your lesson
“Adding and subtracting (age 10+) 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
- Place-value grid (ones / tenths)
- Pencil
Extra for the adult
Worked example. Three tenths on the grid is 0.3.
Optional challenge. For Adding and subtracting (age 10+), add one harder example after success.
What to notice. Keep one parent note: examples tried; results; support used. This session samples Adding and subtracting (age 10+), not mastery.
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Teaching approaches
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1 approach
Adding and subtracting (age 10+) means practising the idea at the table with counters or paper models and one clear check. We will demo once, then your child tries.
Materials: Place-value grid (ones / tenths); Pencil. Adult shows 0.3 as three tenths on the grid. Child builds three decimal amounts on the grid and reads them aloud. Done: three correct decimal readings. Stop after the fresh check; keep optional challenge for another day.
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Practice this concept
Start practiceAdding and subtracting (age 10+) practice
Practice key ideas from Adding and subtracting (age 10+).
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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
The Pet Snake
Before you open · source notes
The Pet Snake supports adding and subtracting (age 10+). Not every worksheet pack.
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 explain one step of “The Pet Snake” in their own words.
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. “The Pet Snake.” 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
- Solve a two-step word problem involving addition and subtraction of numbers beyond 1,000,000
- Choose between mental, written, and calculator methods for a multi-step problem and justify the choice
- Interpret a real-life context to identify which addition/subtraction operations are needed across multiple steps
“If your child is given a complicated word problem involving large numbers or decimals — like calculating the total cost of several items — can they plan and carry out all the steps correctly?”
Curriculum record
- Type
- Procedural
- Subject
- Mathematics
- Domain
- Addition & Subtraction
- Age range
- Ages 10–12
Standards