Skill: course-build → atomise (architecture, step 6b gate) → write-like-james @ 7d612db
Grade 4 Science — course architecture v1 (provisional, drafted from the atom map)
Status: PROVISIONAL — drafted 28 Sep 2026 from the atom map; awaiting James's sign-off.
Read this in five minutes. Grade 4 Science is ONE course with a fixed order, built the same way as Grade 3. It arranges the 158 Grade 4 atoms into four strands and thirty-seven small topics, each with its own mixed practice, summary video and PP100. Nothing below writes a lesson sentence. The atoms stay where they are: the Science Knowledge Graph's 3-5 registers. Every atom is placed exactly once (checked, see "Checks run"); no atom's prerequisite comes after it.
Decisions I need from you
1. Does Grade 4 physics open straight on friction, or with a short retrieval of Grade 3's forces first?
Grade 4 has no motion atoms: you moved them all into Grade 3. Its first new force idea is friction, whose only prerequisite is Grade 3's "a push or pull can stop a moving thing".
No Grade 4 atom re-teaches balanced and unbalanced forces, so a re-teach would mean new atoms or a lesson with no atom.
Recommendation: open on friction (Topic 1); the strand intro and Topic 1's mixed practice carry two or three retrieval items from Grade 3's balanced-forces topics, and Olivia's wish for cross-grade retrieval is served without a re-teach.
Choices: friction straight away / retrieval items only (as recommended) / a re-teach topic with new atoms.
2. Is the fair test taught on the friction investigation (Topic 2), or somewhere later?
"Test friction on different surfaces" (FOR4-004) needs "keep everything else the same" (SR4-003), so the fair-test lessons must come before or inside it.
Putting the five fair-test lessons and the friction test together makes a six-lesson topic that is one investigation from question to result.
Recommendation: Topic 2 as drawn.
Choices: yes / move the fair test to the energy-changer build (Topic 11) and re-point FOR4-004.
3. Does "Water's states at work" (MAT4-024) stay in Matter, or move next to the water cycle in Earth & Space?
The atom is water freezing, melting and evaporating in everyday scenes. Matter uses it as the reference case for "same material or new material" (Topic 15). The water cycle (Topic 22) uses the same idea seven topics later.
Recommendation: keep it in Matter; Topic 22's intro retrieves it in one line.
Choices: keep / move to open Topic 22.
4. Is a seven-lesson "Design and build an energy changer" (Topic 11) acceptable, or should it split?
It carries four Scientific Reasoning lessons (what counts as success, the limits, design a solution, test the design) around the build itself. The design chain is one investigation; cut in two, the first half has nothing to design and the second has no brief.
Recommendation: keep as one topic, flagged as a split candidate once its PP100 data arrives (the same treatment Grade 3's Topics 1 and 2 got).
Choices: keep at seven / split into "what an energy changer does" and "design and build one".
5. Do the three energy-resource topics (26-28) sit in Earth & Space, or at the end of Physics after circuits?
Wind, moving water, sunlight, plants and the three fuels are Earth's resources (TEKS G4-11, Florida 4.E.6.3), but "moving air and water can turn things" is a Physics atom (ENE4-070).
Recommendation: Earth & Space, after the water cycle and climate, so "where does this come from?" is answered with Earth in view; Topic 11 has already shown a turbine turning.
Choices: Earth & Space (as drawn) / end of Physics.
Applied without asking (your rulings already given): four strands in the order Physics → Matter → Earth & Space → Life; Physics runs Forces then Energy (Motion is all in Grade 3); Scientific Reasoning taught inside the topics that use it, no SR strand test; topics of about three to six atoms, nine too many; the water cycle taught once, here in Grade 4, with the ocean; the Moon "why" atom in, seasons patterns-only; one atom one lesson, video or article; intro per strand and per topic that teaches nothing; mixed practice, summary video and a PP100 per topic; the language rules (Earth's pull, carriers not forms, no "leak" or "lift", "stuff" beside "matter"); grade-4 codes that restate grade-3 content cited on the grade-3 atoms, no clones.
Card 1 — The strands and their order
The call: Physics → Matter → Earth & Space → Life, the Grade 3 order, each with its own intro video and its own end-of-strand test.
| Strand | Topics | Atoms | Why it sits here |
|---|---|---|---|
| Physics | 1-11 | 41 (+9 Scientific Reasoning) | Forces first (friction, magnets), then Energy; the fair test is learnt on friction and used all year; waves come before Earth's seismic waves need them. |
| Matter | 12-15 | 13 | Mixtures and "the mass holds" feed Grade 5's conservation chain; "water's states at work" is banked before the water cycle. |
| Earth & Space | 16-31 | 66 (+3 Scientific Reasoning) | The biggest strand: rocks, slow changes, layers, the water cycle, climate, energy resources, the sky; rock layers must precede Life's fossil reading. |
| Life | 32-37 | 26 | Ends the year; leans on Earth (rock layers, fossils) and Grade 3 Life. |
Scientific Reasoning's 12 atoms are spread through Topics 2, 11 and 24 (Card 3). Total 158 lessons.
Card 2 — The topics
The call: thirty-seven topics, most of three to six lessons; a mixed mastery practice set, a summary video and a PP100 at the end of every one.
| # | Topic (student-facing title) | Atoms (in teaching order) | Lessons | The big idea it serves |
|---|---|---|---|---|
| Physics | ||||
| 1 | Why sliding things stop | FOR4-001, 002, 003, 005 | 4 | Where two surfaces rub there is a force against sliding: friction; rough slides less; friction helps and hinders |
| 2 | A fair test | SR4-001, 002, 003, 004, 005, FOR4-004 | 6 | A question you can test; change one thing; keep the rest the same; measure the result; then test friction on different surfaces for real |
| 3 | Magnets, properly | FOR4-010, 011, 012, 013, 014 | 5 | Only some metals; two poles; like poles push, unlike pull; closer is stronger; draw the force |
| 4 | Energy moves from giver to receiver | ENE4-001, 002, 003 | 3 | Energy passes from one thing to another; light, sound, electricity and heat carry it; some carriers need no touch |
| 5 | Bumps and crashes | ENE4-004, 005, 006, 010 | 4 | A moving object hands over energy when it hits; predict the collision; the sound and warmth are energy too; faster means more |
| 6 | Heat flows from hot to cold | ENE4-020, 021, 022, 023 | 4 | Heat always flows hot to cold; temperatures change as it flows; conductors and insulators; why metal feels cold |
| 7 | Sound and sight: what reaches your ear and eye | ENE4-030, 031, 032, 050, 051 | 5 | Faster vibration, higher pitch; stronger vibration, louder; you see a thing only when light from it reaches your eye |
| 8 | Waves carry a pattern | ENE4-040, 041, 042, 043, 044 | 5 | A wave carries energy, not water; amplitude and wavelength; draw it; a pattern can carry a message |
| 9 | A circuit is a loop | ENE4-060, 061, 062, 066 | 4 | The bulb lights only when the loop is complete; build one; electrical conductors and insulators |
| 10 | What a circuit gives out | ENE4-063, 064, 065 | 3 | Each part has a job; the current carries the energy; the circuit gives out light, sound, heat or motion |
| 11 | Design and build an energy changer | ENE4-070, 071, SR4-020, 021, 022, ENE4-072, SR4-023 | 7 | Moving air or water can turn things; spot the energy change in a device; say what counts as success and the limits; design, build, test against the rule (7 lessons: one investigation; split candidate, see Decision 4) |
| Matter | ||||
| 12 | Same material, same behaviour | MAT4-001, 002, 003 | 3 | Every piece of one material floats or sinks the same way; pick out the sample that matches two properties |
| 13 | Mixtures and solutions | MAT4-020, 021, 022, 023 | 4 | Mixed things are each still themselves; a solution is a mixture you cannot see through the parts of; dissolved is not gone |
| 14 | Break it, mix it: the mass holds | MAT4-040, 041, 042 | 3 | Break a thing into pieces or mix two things and the total mass stays the same |
| 15 | New material, or the same one changed? | MAT4-024, 060, 061 | 3 | Water frozen, melted or evaporated is still water; some changes make a new material; the clue is a changed characteristic |
| Earth & Space | ||||
| 16 | What a rock is made of | EAR4-001, 002, 003 | 3 | Describe a rock by its grains and shine; rocks are made of minerals; test a mineral to tell it apart |
| 17 | Rock from cooling, rock from settling | EAR4-007, 008, 009, 010 | 4 | Igneous rock: what it looks like, how melted rock cooled into it; sedimentary rock: what it looks like, how settled pieces pressed into it |
| 18 | Rock changed by heat and squeezing; sorting the three families | EAR4-011, 012, 005, 006 | 4 | Metamorphic rock: what it looks like, how heat and pressure changed it; sort a rock into its family; which rocks can hold water or oil |
| 19 | Weathering, erosion, deposition | EAR4-020, 021, 022, 023, 024, 025 | 6 | Breaking in place, carrying away, dropping; what does each; then the sort |
| 20 | Layers tell the time | EAR4-035, 036, 037, 038 | 4 | Deeper is older; put layers in order; a fossil is as old as its layer; read the landscape's story |
| 21 | Earthquakes and seismic waves | EAR4-045, 046, 047 | 3 | Earth's rocky crust; the shaking spreads as waves (Topic 8); compare two defences |
| 22 | The water cycle | EAR4-053, 054, 055, 056, 057 | 5 | Water falls, gathers, evaporates and condenses in a loop; the Sun's energy drives it; predict the drop's next step |
| 23 | Earth's water and the ocean | EAR4-058, 059, 060, 061, 062 | 5 | Where Earth's water sits; why fresh water matters; the ocean feeds the cycle and connects all the water; build the model |
| 24 | Weather or climate? | EAR4-070, 071, SR4-010, 011, 012, EAR4-072 | 6 | Weather is today, climate is the usual pattern; make a bar graph of records; compare two places; one odd day does not change the climate; read the climate off the records |
| 25 | Earth's parts act on one another | EAR4-026, 080, 081 | 3 | Read Earth's features from a map; water, air, land and living things act on each other; spot the interaction |
| 26 | Energy from wind, water, sunlight and plants | EAR4-083, 084, 085, 086 | 4 | Four sources nature keeps giving |
| 27 | Fuels dug, pumped and piped from the ground | EAR4-087, 088, 089 | 3 | Coal, oil, natural gas: what each is and where it comes from |
| 28 | Renewable or not? Weighing up an energy source | EAR4-090, 094, 091, 092, 093 | 5 | Renewable means nature keeps up; nonrenewable means it cannot; sort the seven sources; using any source leaves a mark; weigh one up |
| 29 | The Sun's path and the seasons | SPA4-001, 002, 003, 004 | 4 | The Sun's daily path; longer and shorter days through the year; read a season from its data; predict the next step (patterns only, no tilt) |
| 30 | The turning Earth and the stars | SPA4-007, 008, 005, 006, 009 | 5 | Earth spins once a day; a year is one orbit; star patterns keep their shapes; different stars in different seasons; the turning Earth moves the whole sky |
| 31 | The Moon's changing shape | SPA4-020, 021, 022, 023, 024 | 5 | The shape seems to change; name the shapes; order them; predict the next; why it seems to change |
| Life | ||||
| 32 | Parts with jobs: inside animals, and in plants | LIF4-001, 002, 003 | 3 | Match an internal part to its job; plant structures for tough places; from sense to brain to action |
| 33 | Plants make their own food | LIF4-010, 011, 012 | 3 | Plants make food from sunlight; animals cannot; trace the energy from the Sun to the eater |
| 34 | Producers, consumers, decomposers | LIF4-020, 021, 022, 025, 023, 024 | 6 | What each is; decomposers feed the soil; sort organisms by feeding role; read a food web |
| 35 | Inherited or picked up; instinct or learned | LIF4-030, 034, 031, 032, 033 | 5 | Traits from parents, traits from life; sort them; when both play a part; instinct or learned behaviour |
| 36 | From flower to seed to seedling | LIF4-040, 041, 042, 043, 044 | 5 | Pollination, seed forming, seeds travelling, germination; complete change or gradual growth in animal life cycles |
| 37 | When the place changes | LIF4-045, 050, 051, 052 | 4 | Seasons differ from place to place; fossils show past environments; some kinds have gone forever; adapt or go extinct |
Totals: 158 lessons, 37 practice sets, 37 PP100s (banks of at least 50 items each), 4 strand tests (after Topics 11, 15, 31, 37), 1 end-of-grade test.
Why this grouping
- Every prerequisite edge points backwards in this order or into Grade 3. Checked atom by atom in the assembled files (see "Checks run"); no forward reference.
- Topic 2 puts the fair test right where it is first needed (FOR4-004 requires SR4-003), so every later investigation in the year can call on it.
- Topic 8 (waves) sits before Topic 21 (seismic waves need ENE4-040); Topic 20 (rock layers) sits before Topic 37 (reading past environments needs EAR4-036).
- The rock families are taught one family at a time, what it looks like then how it forms, and only then the sort (your 25 September ruling on the six per-family atoms). Topics 17 and 18 split them so no topic reaches seven.
- Energy resources follow Olivia's rule of surprising members first: wind, water, sunlight and plants (Topic 26) before the fuels everyone already calls "energy" (Topic 27), then the renewable-or-not sort on all seven (Topic 28).
- Topic 7 pairs sound and sight because both answer one question, "what has to reach you for you to hear or see?"; the two seeing atoms are too few for a topic of their own.
- One topic reaches seven lessons (Topic 11); Decision 4 asks about it. None reaches eight.
What changes: on sign-off the folder gets grade4/topicNN_build/ per topic; Topic 1's blueprint is drafted first.
Card 3 — Scientific Reasoning is taught where it is used
The call: each of the 12 Scientific Reasoning atoms is a lesson inside the topic that first needs it, with its check there; no separate strand, no separate test.
| SR atom | Host topic | Why there |
|---|---|---|
| SR4-001 A question you can test; SR4-002 The one thing you change; SR4-003 Keep everything else the same; SR4-004 What you measure to see the result; SR4-005 Fair test or unfair test? | 2 A fair test | the friction test (FOR4-004) is the first investigation of the year and requires SR4-003 |
| SR4-020 What counts as success; SR4-021 The limits you must work within; SR4-022 Design a solution; SR4-023 Test the design against the rule | 11 Design and build an energy changer | the first build of the year; the design chain wraps the build (ENE4-072) |
| SR4-010 Construct a bar graph; SR4-011 Compare two sets of results; SR4-012 The result that doesn't fit | 24 Weather or climate? | monthly records make the first bar graph students build; two towns' records are the two sets; one freak day is the result that does not fit and does not change the climate |
Card 4 — Tests and benchmarks
The call: a PP100 per topic; a static end-of-strand test per strand (some free response); one static end-of-grade test; all Grade 4 tests are our own banks, seeded from released grade-5 items filtered to Grade 4 atoms.
- No state tests science at grade 4 (D1 ruling). The released STAAR, Florida SSA and AZSCI grade-5 forms are cumulative over grades 3-5, so their items tagged to Grade 4 atoms seed the banks and set the style.
- Grade 4 content the grade-5 tests lean on hardest: the water cycle and the ocean (Topics 22-23, STAAR 5.10A builds on them), weathering-erosion-deposition (Topic 19, feeds STAAR 5.10C landforms), circuits (Topics 9-10, feeds 5.8B), mixtures and "the mass holds" (Topics 13-14, feed 5.6B and 5.6C), food webs and producers-consumers-decomposers (Topic 34, feeds 5.12B), the Moon's shapes and Earth's spin (Topics 30-31, feed 5.9A).
- The strand tests fall after Topics 11, 15, 31 and 37.
- The end-of-grade test samples all four strands with free-response items.
Checks run (28 Sep 2026)
- Atoms placed: 158 = atoms in the Grade 4 registers (FOR4 10, ENE4 31, MAT4 13, EAR4 52, SPA4 14, LIF4 26, SR4 12). Every atom appears in exactly one topic; none is left over; none is doubled.
- Prerequisites: every prerequisite of every Grade 4 atom sits in an earlier topic of this plan, earlier in the same topic, or in Grade 3. Checked mechanically against the assembled atom files (
data/atoms/03-05/, cross-strand XREFs resolved to atom codes). Zero violations. - Topics of 7+: one (Topic 11). Topics of 2 or fewer: none.
What happens next
You rule on the five decisions and the table. Then Topic 1 ("Why sliding things stop") gets its blueprint in the Grade 3 shape — decisions first, lessons at a glance, lesson cards — and the Grade 3 Forces golden pack is checked for reuse (FOR3-003's "a push or pull can stop a moving thing" is friction's doorway).