JAXILLMIND FAMILY · JAXON · GRADE 4 · 4.NBT.B.4
ADD AND SUBTRACT MULTI-DIGIT NUMBERS
L1 · Remember
Work it out, place by place.
Level 1
Right 0
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Learn this first
Add and subtract one PLACE at a time, right to left.
Each place is worth ten of the place to its right, so ten ones become one ten — that is what carrying is. Borrowing is the same trade run backwards: one ten becomes ten ones.
Example: 527 + 384: ones 7+4=11 (write 1, carry 1); tens 2+8+1=11 (write 1, carry 1); hundreds 5+3+1=9 → 911.
Tap Start to play — spot the answer!
Keep going — this game grows with you
- L1 RememberRecall the fact.
- L2 UnderstandExplain what the number means.
- L3 ApplyUse it to solve a problem.
- L4 AnalyzeBreak the problem into parts.
- L5 EvaluateJudge whether an answer is sound.
- L6 CreateBuild a problem of your own.
Starts at L1 · climbs to L6 — analyze, evaluate and create, not just remember.
TTCF — capability · time bar · failure mode · detection
| Capability | TTC | Failure mode | Detection |
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Source: products/xml/games/family/jaxon-math-g4-L1.xml v0.1 · engine "choice" · compiled by gen-brain-game.mjs · gated by check-brain-game.mjs