PAGE 1
SUBJECTNEST · YEAR 2 MATHEMATICS · WEEKS 9–10 · n-first-key
n-first · Paper-puzzle order
Complete source (staff reference): Original fictional label numbers: 507, 570, 750. Chosen
amount to represent: 507. Two pretend card groups contain 38 and 27 cards. A separate
pretend project needs 73 labels and has 29 ready. These are supplied mathematical
quantities, not actual stock, price, creation or a child result. All quantities can be read
aloud; no object handling is required.
Question: Put 507, 570, 750 in numerical order. Show or direct a labelled number line and
explain one comparison.
Complete key and accepted variations: Order: 507 < 570 < 750. A labelled line with
relevant hundred reference points and consistent equal intervals can show this order; exact
pixel position is not a compulsory measurement. Explain comparison by hundreds then
tens/ones, not digit width.
Component criterion: Orders all numerals by magnitude, supports a comparison and uses a
meaningful labelled line.
Specific unrelated next teaching: If highest digit decides order, use unrelated192/219 with
named hundreds. If line positions unlabelled, make a new200→300 scale before another
placement.
Question: Show 507 using hundreds, tens and ones. Show a different valid partition and
explain the zero in its standard form.
Complete key and accepted variations: 507 = 5 hundreds0 tens7 ones = 4 hundreds10
tens7 ones. Check 500+0+7 = 400+100+7. Other nonnegative whole-unit partitions
summing507 accepted. Zero is no tens in standard form, not no total value.
Component criterion: Names standard places, keeps zero meaning and preserves value in a
distinct alternate partition.
Specific unrelated next teaching: If exchange changes value, use unrelated34:3 tens4
ones↔2 tens14 ones and recount. If zero removed, compare204/240; do not teach by
revealing this held amount.
Question: How many cards are in the two groups together? Show your chosen number
sentence and strategy. Check it.
Complete key and accepted variations: 38+27=65 cards. Example partition
30+20+8+7=65; regroup the ones where useful. Counted marks, bridge or another valid
own strategy accepted. Inverse check 65−27=38.
Component criterion: Chooses join/addition model and a valid conserved strategy/check,
with card meaning.
SubjectNest / NeuroForge 2026 · Original expression CC BY 4.0; separate terms accompany.
Keep complete notices and inert source/rights PDF attachments.
1

PAGE 2
SUBJECTNEST · YEAR 2 MATHEMATICS · WEEKS 9–10 · n-first-key
Specific unrelated next teaching: If a bridge double-counts, split unrelated18+5 as+2
then+3; if concatenation occurs, recombine20+10+7+6. Ask for a new inverse check after
teaching.
Question: How many more labels does the separate project need? Choose a representation
and strategy; explain and check what your answer means.
Complete key and accepted variations: 29+?=73, or73−29=44. Count up
29→30(+1)→73(+43); parts sum44. A correctly represented other strategy is accepted.
Answer44 more labels, checked by29+44=73, not need+ready. No actual supplies/delivery.
Component criterion: Selects the missing part, represents/solves/checks it and
communicates contextual meaning.
Specific unrelated next teaching: If need+ready is used, model unrelated25 needed/17
ready with a missing portion. If no units, ask what8 would count in that new model; choose
a fresh ordinary problem afterwards.
Record honestly: full source familiarity/exposure; question and actual first
response/method; reading/scribing/handling access; mathematical hints/device answers;
observed child choices versus adult operations; actual teaching/source/date; interval before
next source; initial versus supported revision; unattempted/uncaptured fields. No
hypothetical learner score or attained level.
SubjectNest / NeuroForge 2026 · Original expression CC BY 4.0; separate terms accompany.
Keep complete notices and inert source/rights PDF attachments.
2

FULL NO-IMAGE / LINEAR SOURCE
## n-first · Paper-puzzle order

**Complete source (staff reference):** Original fictional label numbers: 507, 570, 750. Chosen amount to represent: 507. Two pretend card groups contain 38 and 27 cards. A separate pretend project needs 73 labels and has 29 ready. These are supplied mathematical quantities, not actual stock, price, creation or a child result. All quantities can be read aloud; no object handling is required.

**Question:** Put 507, 570, 750 in numerical order. Show or direct a labelled number line and explain one comparison.

**Complete key and accepted variations:** Order: 507 < 570 < 750. A labelled line with relevant hundred reference points and consistent equal intervals can show this order; exact pixel position is not a compulsory measurement. Explain comparison by hundreds then tens/ones, not digit width.

**Component criterion:** Orders all numerals by magnitude, supports a comparison and uses a meaningful labelled line.

**Specific unrelated next teaching:** If highest digit decides order, use unrelated192/219 with named hundreds. If line positions unlabelled, make a new200→300 scale before another placement.

**Question:** Show 507 using hundreds, tens and ones. Show a different valid partition and explain the zero in its standard form.

**Complete key and accepted variations:** 507 = 5 hundreds0 tens7 ones = 4 hundreds10 tens7 ones. Check 500+0+7 = 400+100+7. Other nonnegative whole-unit partitions summing507 accepted. Zero is no tens in standard form, not no total value.

**Component criterion:** Names standard places, keeps zero meaning and preserves value in a distinct alternate partition.

**Specific unrelated next teaching:** If exchange changes value, use unrelated34:3 tens4 ones↔2 tens14 ones and recount. If zero removed, compare204/240; do not teach by revealing this held amount.

**Question:** How many cards are in the two groups together? Show your chosen number sentence and strategy. Check it.

**Complete key and accepted variations:** 38+27=65 cards. Example partition 30+20+8+7=65; regroup the ones where useful. Counted marks, bridge or another valid own strategy accepted. Inverse check 65−27=38.

**Component criterion:** Chooses join/addition model and a valid conserved strategy/check, with card meaning.

**Specific unrelated next teaching:** If a bridge double-counts, split unrelated18+5 as+2 then+3; if concatenation occurs, recombine20+10+7+6. Ask for a new inverse check after teaching.

**Question:** How many more labels does the separate project need? Choose a representation and strategy; explain and check what your answer means.

**Complete key and accepted variations:** 29+?=73, or73−29=44. Count up 29→30(+1)→73(+43); parts sum44. A correctly represented other strategy is accepted. Answer44 more labels, checked by29+44=73, not need+ready. No actual supplies/delivery.

**Component criterion:** Selects the missing part, represents/solves/checks it and communicates contextual meaning.

**Specific unrelated next teaching:** If need+ready is used, model unrelated25 needed/17 ready with a missing portion. If no units, ask what8 would count in that new model; choose a fresh ordinary problem afterwards.

**Record honestly:** full source familiarity/exposure; question and actual first response/method; reading/scribing/handling access; mathematical hints/device answers; observed child choices versus adult operations; actual teaching/source/date; interval before next source; initial versus supported revision; unattempted/uncaptured fields. No hypothetical learner score or attained level.





