Topic 1 — Why sliding things stop — blueprint for James
What I need from you: 3 decisions
Do we keep the air out of friction in Grade 4, so a thrown ball "rubs against nothing"?
the register's friction atoms are about two surfaces rubbing (a box on a floor, a car on carpet). Air resistance is in no 3-5 framework and arrives with Grade 5's forces.
a thrown ball is the cleanest non-example of surfaces rubbing, but a child who has heard of "air resistance" could object.
My recommendation: keep the air out; the non-example is a thing touching no surface, and the article names the simplification in one line ("the air pushes a little too; that comes later"). Keep the air out / mention air resistance by name.
Do we say "more friction", or "stronger friction" as Grade 3 says of forces?
Grade 3 taught every force as strong or weak (a stronger push makes a bigger change). TEKS 4.7A, the state tests and every classroom say "more friction".
one name per concept matters, but a child who meets "more friction" on a test and never heard it in the course is worse off than one who met both with the link said.
My recommendation: "more friction" and "less friction" as the working words, with one line in L03 saying "more friction means a stronger push against the sliding". More / stronger / both as recommended.
Which lessons get a video?
something moves in L01 (the box slides and stops), L02 (the ball rolls to a stop on the grass) and L03 (the same car on two floors); L04 is a sort of described scenes.
My recommendation: all four scripted; L04 marked "could do without". All four / L04 article only.
Topic 1 at a glance — 4 lessons
| Lesson | Opens on | Format | |
|---|---|---|---|
| L01 | Spot the friction | Elena pushes a cardboard box full of books across the classroom floor. | video + article |
| L02 | Why sliding things stop | Carmen rolls a ball across the grass and lets go. | video + article |
| L03 | Which surface lets it slide farther? | Darnell gives a toy car the same gentle push on the wooden floor and then on the carpet. | video + article |
| L04 | Helpful friction, unhelpful friction | On an icy morning Reed steps onto the path and his foot slides out from under him. | little; the sort is of described scenes — could do without a video (decision 3). |
What this topic is, in five lines
Four lessons, one per atom: FOR4-001, 002, 003, 005.
Term coined here: friction (L01). "Rough", "smooth", "helpful" and "unhelpful" are everyday words, not coined.
Deliberately not taught: the fair test and the friction investigation (Topic 2); air resistance (Grade 5); heat from rubbing as a lesson (Grade 3 Energy); magnets (Topic 3).
PP100 cluster: the whole topic, capstone FOR4-005 (the helpful / unhelpful sort carries every earlier idea).
Applied without asking (rulings you have already given): one atom, one lesson, video and article; the example sequence for every sort (examples, near-miss non-examples, the rule last); the headache's question asks about the happening, the name arrives in the forest line; a fluency quiz after every coining part, recognition before recall, "friction" chosen before it is typed; one attached easy question after "Okay, now your turn" on every lesson video and three on the summary; the intro at most 120 words with a ready line and a poll; the summary at most 175 words opening "Here's everything we found out about why sliding things stop" and recapping each lesson's point, not its examples; Grade 3's wording for FOR3-003 kept as the doorway ("a moving thing does not stop by itself; stopping needs a force too"); "pushes against" as the verb for what the surface does (the catalogue's note on FOR-08); heat from rubbing mentioned in one article line only (ENE3's atom, "may mention"); three retrieval items from Grade 3 in the mixed practice (a push or pull can stop things; balanced forces; a stronger push makes a bigger change); every student sentence has a subject and a verb; units as words; names a child can spell, one topic each (Elena, Carmen, Darnell and Reed are this topic's); US spelling; colour drawings by code.
Misconceptions exposed (atomise step 3, from the elementary physics catalogue)
| Row | The child's belief | Where this topic meets it |
|---|---|---|
| FOR-01 | the push is inside the ball and runs out, so it stops | confront in L02: the ball on the grass stops because the grass pushes against it; the same ball on a smooth floor keeps going; the quiz's claim item is "the push ran out" |
| FOR-02 | a moving thing needs something pushing it to keep moving | confront in L02 by the smooth-floor contrast (less friction, the ball rolls on with nobody pushing); the full case is Grade 3 Topics 9 and 10 |
| FOR-08 | friction only slows things; it is a nuisance, not a real force | confront in L04: helpful cases first (the shoe on the path, the bike brake, the match), then the squeaky hinge |
| FOR-12 | the force is how far it went | avoid in L03 by wording: the same push every time, the surface is what changes; distance is the evidence of less friction, never a measure of the push |
Spot the friction L01
Elena pushes a cardboard box full of books across the classroom floor.
The box slides, but it is hard work.
When Elena stops pushing, the box slides a little and stops.
Nobody is pulling the box back.
So what is working against Elena's push?
Where the bottom of the box rubs against the floor, a force pushes against the sliding.
You cannot see this force, but Elena can feel it in her arms.
Every time two surfaces rub, this force is there, and it always pushes against the sliding.
The force that acts where two surfaces rub, against the sliding, is called friction.
Video: the box slides, slows and stops with the rubbing surfaces lit; an arrow against the sliding appears where the box meets the floor — video and article.
Part 1 — FOR4-001 — Identify friction as the force that acts where two surfaces rub, against the sliding; coin friction
Part 1q — Fluency quiz: friction
Why sliding things stop L02
Carmen rolls a ball across the grass and lets go.
The ball rolls, slows down, and stops.
Nobody touched the ball after Carmen let go.
Why did the ball stop?
A moving thing does not stop by itself, so something pushed against the ball.
Where the ball rubs against the grass, friction pushes against the rolling.
Friction slows the ball a little more every moment, until it stops.
The ball did not run out of push; friction stopped it.
On a smooth floor there is less friction, so the same ball rolls much farther before it stops.
Video: the ball rolling to a stop on the grass with the friction arrow at the contact, then the same ball on the smooth hall floor rolling on and on — video and article.
Part 1 — FOR4-002 — Explain that a sliding or rolling thing slows because friction acts on it, not because its push runs out
Which surface lets it slide farther? L03
Darnell gives a toy car the same gentle push on the wooden floor and then on the carpet.
On the wooden floor the car rolls all the way to the far wall.
On the carpet the car stops after a few steps.
The push was the same both times.
So why does the car go so much farther on the wood?
The carpet is rough, so the car's wheels rub against it hard.
There is more friction on the carpet, so the car stops sooner.
The wooden floor is smooth, so the wheels rub against it only a little.
There is less friction on the wood, so the same push takes the car farther.
A smoother surface means less friction, so the same thing slides farther on it.
Video: the same car, the same push, two floors in turn; the rough and smooth surfaces shown close up; the stopping points marked — video and article.
Part 1 — FOR4-003 — Predict which surface lets the same object slide farther by comparing how rough or smooth each surface is
Helpful friction, unhelpful friction L04
On an icy morning Reed steps onto the path and his foot slides out from under him.
On the dry path his shoe grips and he walks on.
Friction is what made the difference.
Was friction a nuisance here, or was it what kept Reed on his feet?
Friction under Reed's shoe lets his foot push off the ground, so he can walk.
With almost no friction on the ice, his foot slides and he falls.
Here, friction is helpful.
A door hinge that squeaks and sticks has friction too, and there it is unhelpful.
Friction is the same force in both places; it is helpful when you want the grip, and unhelpful when you want the sliding.
Video: little; the sort is of described scenes — could do without a video (decision 3).
Part 1 — FOR4-005 — Sort situations by whether friction there is helpful or unhelpful
Questions the blueprint cannot settle alone
- Whether Topic 1's intro scene is the sled on grass and snow (friction without the word) or the ball that stops on grass and not on the gym floor; both coin nothing. My call is the sled, so L02's ball stays fresh.
- Whether the Grade 3 Topic 7 lesson "A push or pull can slow or stop things" should be linked from L02's page as the retrieval, or only recalled by its one item.
This grade’s course architecture — open only if you want the whole map
Skill: course-build → atomise (architecture re-check, steps 6b/6c) → write-like-james @ df153ae
Grade 4 Science — course architecture v2 (re-checked 2 October 2026 against every ruling since 28 September)
Status: PROVISIONAL — in force from 2 October 2026 under James's ruling "build straight away"; any line he objects to is changed, nothing waits for a click.
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 five strands and thirty-eight small topics, each with its own summary video, mixed practice 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; no atom's prerequisite comes after it (checked again on 2 October, see "Checks run").
Decisions I need from you
The first two changed since the 28 September plan. The other four are the 28 September questions, still open, with the same recommendations. I am building on every recommendation below; say so if you want any of them the other way.
1. Is engineering design its own strand in Grade 4, two topics long, placed after Physics?
Context: you said on 1 October "in Grade 4 we may want to consider it as a separate strand". The Grade 4 design atoms are four: what a design must do, what it must stay inside, design a solution, test the design against the rule.
Context: the three-lesson demo you reviewed on 2 October (the bird feeders) already teaches the first three, in the course schema, videos rendered. The fourth needs the fair test (Topic 2) and a real build to test, and the energy-changer build (NGSS 4-PS3-4, "design, test and refine a device that converts energy") is that build.
Recommendation: a fifth strand, "Design and build", of two topics after Physics: Topic 11 is the demo as built (3 lessons); Topic 12 "How to build and test an energy changer" (4 lessons: moving air and water turn things, spot the energy change, build the changer, test it against the rule). The 28 September plan's seven-lesson Topic 11 goes away. The strand gets its own short intro video and NO end-of-strand test (two PP100s certify seven atoms).
Choices: fifth strand as recommended / weave the four atoms into Physics as one seven-lesson topic (the 28 September plan) / fifth strand but with a strand test too.
2. Does the summary video come before the mixed practice in Grade 4?
Context: for the demo on 2 October you ruled "the summary comes BEFORE the mixed practice". Grade 3 runs practice → summary → PP100 (the 25 September ruling for grades 3-8).
Context: with the summary first, the child hears every rule once, then practises, then sits the PP100 with the practice fresh. The page order is a one-line flag per topic; Grade 3 is untouched until you say.
Recommendation: yes, summary → practice → PP100 for Grade 4.
Choices: yes / keep Grade 3's order (practice → summary → PP100) / change Grade 3 too.
3. Does Grade 4 physics open straight on friction, with retrieval items from Grade 3 instead of a re-teach?
Context: Grade 4 has no motion atoms and nothing re-teaches balanced and unbalanced forces; friction's only prerequisite is Grade 3's "a push or pull can slow or stop things".
Context: Olivia asked for cross-grade retrieval; two or three Grade 3 items in Topic 1's practice set give it without a re-teach lesson.
Recommendation: friction first; retrieval items only.
Choices: as recommended / a re-teach topic with new atoms.
4. Is the fair test taught on the friction investigation (Topic 2)?
Context: "test friction on different surfaces" needs "keep everything else the same", so the five fair-test lessons come just before it, in one six-lesson topic that is one investigation from question to result.
Recommendation: yes, Topic 2 as drawn.
Choices: yes / move the fair test to the energy-changer build.
5. Does "water's states at work" stay in Matter, next to "same material or new material"?
Context: Matter uses water freezing, melting and evaporating as its reference case for "same material, changed". The water cycle (Topic 23) uses the same idea seven topics later and retrieves it in one line.
Recommendation: keep it in Matter.
Choices: keep / move to open the water cycle.
6. Do the three energy-resource topics sit in Earth & Space, after the water cycle and climate?
Context: wind, moving water, sunlight, plants and the three fuels are Earth's resources (TEKS 4.11, Florida 4.E.6.3); the one Physics atom among them (moving air and water can turn things) is taught in Topic 12.
Recommendation: Earth & Space, as drawn.
Choices: Earth & Space / end of Physics.
Applied without asking (your rulings already given): the strand order Physics → Matter → Earth & Space → Life, with Design and build slotted after Physics (decision 1); Scientific Reasoning taught inside the topics that use it, no SR strand test; topics of three to six atoms, none over six; the water cycle taught once, here, with the ocean; the Moon "why" atom in, seasons patterns-only; one atom one lesson, video or article; an intro per strand and per topic that teaches nothing; "criterion" and "constraint" ARE coined in Grade 4 and used from then on (your demo notes of 2 October: "we already have introduced criterion and constraint so that's what we should be using now"), so the register's SR4-021 note "everyday wording only" is proposed for retirement in the knowledge-graph repo; the pattern-and-predict practice sits where the pattern is the science (the Sun's path, the seasons, the Moon's shapes, which are already atoms there), with "a pattern is something that happens again and again in the same way"; predator and prey are Grade 5 words, Grade 4 says "the fox eats the rabbit"; every topic title fits the frame "Here's everything we found out about ___"; the language rules (Earth's pull, carriers not forms, no "leak" or "lift", "stuff" beside "matter", "density" named); grade-4 codes that restate grade-3 content are cited on the grade-3 atoms, no clones; the strand tests are placeholders until Becky's format gate is passed (Grade 3's proposal of 30 September applies as written); names a child can spell, one topic each, US animals, US spelling; "strand" never said to a student.
Card 1 — The strands and their order
The call: Physics → Design and build → Matter → Earth & Space → Life, each with its own intro video; a strand test after Physics, Matter, Earth & Space and Life (placeholders under Becky's validation), none after Design and build.
| Strand | Topics | Atoms | Why it sits here |
|---|---|---|---|
| Physics | 1-10 | 38 (+5 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. |
| Design and build | 11-12 | 3 (+4 Scientific Reasoning) | Needs the fair test (Topic 2) and energy transfer (Topic 4); the energy-changer build is the design the child tests. |
| Matter | 13-16 | 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 | 17-32 | 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 | 33-38 | 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, 12 and 25 (Card 3). Total 158 lessons.
Card 2 — The topics
The call: thirty-eight topics of three to six lessons; a summary video, a mixed mastery practice set and a PP100 at the end of every one. Every topic is one PP100 cluster, closed by the capstone atom named in the last column.
| # | Topic (student-facing title) | Atoms (in teaching order) | Lessons | The big idea it serves | PP100 capstone |
|---|---|---|---|---|---|
| Physics | |||||
| 1 | Why sliding things stop | FOR4-001, 002, 003, 005 | 4 | Where two surfaces rub there is a force against sliding: friction; a smoother surface lets things slide farther; friction helps and hinders | FOR4-005 helpful or unhelpful friction (the sort) |
| 2 | How to run 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; fair or unfair; then test friction on different surfaces for real | FOR4-004 the friction test (the routine run) |
| 3 | How magnets push and pull | FOR4-010, 011, 012, 013, 014 | 5 | Only some metals; two poles; like poles push apart, unlike pull together; closer is stronger; draw the force | FOR4-014 model a magnetic force |
| 4 | How energy moves from one thing to another | ENE4-001, 002, 003 | 3 | Energy passes from a giver to a receiver; light, sound, electricity and heat carry it; some carriers need no touch | ENE4-003 transfer without touching |
| 5 | What happens when things bump into each other | 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 | ENE4-010 evidence links speed to energy |
| 6 | How heat moves 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 | ENE4-023 why metal feels colder |
| 7 | What reaches your ears and your eyes | 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; why the dark hides everything | ENE4-051 why the dark hides everything |
| 8 | How waves carry energy and messages | ENE4-040, 041, 042, 043, 044 | 5 | A wave carries energy, not water; amplitude and wavelength; draw it; a pattern can carry a message | ENE4-044 send a message with a pattern |
| 9 | How a circuit makes a bulb light | ENE4-060, 061, 062, 066 | 4 | The bulb lights only when the loop is complete; will it light; build one; electrical conductors and insulators | ENE4-066 the conductor / insulator sort |
| 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, heat, sound or motion | ENE4-065 what the circuit gives out |
| Design and build | |||||
| 11 | What a design must do, and what it must stay inside | SR4-020, 021, 022 | 3 | A job the design must do is a criterion; a limit it must stay inside is a constraint; write both down, then keep or cross out each idea against them (the demo of 2 October, adopted as built) | SR4-022 check the idea before you build |
| 12 | How to build and test an energy changer | ENE4-070, 071, 072, SR4-023 | 4 | Moving air or water can turn things; spot the energy change in a device; build an energy changer to a criterion and a constraint; test it against the rule with the same fair test for every design | SR4-023 test the design against the rule |
| Matter | |||||
| 13 | How to tell materials apart | MAT4-001, 002, 003 | 3 | Every piece of one material floats or sinks the same way; floater or sinker is a property of the material; pick out the sample that matches two properties | MAT4-003 the two-property pick |
| 14 | What mixtures and solutions are | MAT4-020, 021, 022, 023 | 4 | Mixed things are each still themselves; a solution is a mixture you cannot see the parts of; dissolved is not gone | MAT4-023 dissolved is not gone |
| 15 | Why the mass stays the same | MAT4-040, 041, 042 | 3 | Break a thing into pieces or mix two things and the total mass stays the same; predict the balance | MAT4-042 mix it, the mass holds |
| 16 | When a change makes a new material | 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 | MAT4-061 the clue is a changed characteristic |
| Earth & Space | |||||
| 17 | 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 | EAR4-003 test a mineral |
| 18 | How igneous and sedimentary rock form | 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 | EAR4-010 how sedimentary rock forms |
| 19 | The three rock families | EAR4-011, 012, 005, 006 | 4 | Metamorphic rock: what it looks like, how heat and squeezing changed it; sort a rock into its family; which rocks can hold water or oil | EAR4-005 sort a rock into its family |
| 20 | How rock breaks, moves and settles | EAR4-020, 021, 022, 023, 024, 025 | 6 | Weathering breaks rock in place; erosion carries the pieces; deposition drops them; what does each; then the sort | EAR4-025 weathering, erosion or deposition? |
| 21 | How rock 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 | EAR4-038 read the landscape's story |
| 22 | What happens in an earthquake | EAR4-045, 046, 047 | 3 | Earth's rocky crust; the shaking spreads as waves (Topic 8); compare two defences | EAR4-047 compare two hazard defences |
| 23 | 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 | EAR4-057 predict the drop's next step |
| 24 | Where Earth's water is | 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 | EAR4-062 build the water cycle model |
| 25 | Weather and 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 | EAR4-072 work out the climate from records |
| 26 | How 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 | EAR4-081 spot the interaction |
| 27 | Energy from wind, water, sunlight and plants | EAR4-083, 084, 085, 086 | 4 | Four sources nature keeps giving | EAR4-086 plants as an energy resource (last of the four) |
| 28 | Fuels from under the ground | EAR4-087, 088, 089 | 3 | Coal, oil, natural gas: what each is and where it comes from | EAR4-089 natural gas (last of the three) |
| 29 | Which energy sources nature can replace | 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 | EAR4-093 weigh up an energy source |
| 30 | 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) | SPA4-004 predict the next step in a seasonal pattern |
| 31 | 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 | SPA4-009 a turning Earth moves the whole sky |
| 32 | 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 | SPA4-024 why the Moon's shape seems to change |
| Life | |||||
| 33 | Parts and their jobs, inside animals and plants | LIF4-001, 002, 003 | 3 | Match an internal part to its job; plant structures for tough places; from sense to brain to action | LIF4-003 from sense to brain to action |
| 34 | How 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 | LIF4-012 trace the energy from the Sun |
| 35 | Producers, consumers and 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 ("the fox eats the rabbit", no predator or prey) | LIF4-024 read a food web |
| 36 | Traits from parents, and traits from life | LIF4-030, 034, 031, 032, 033 | 5 | Traits from parents, traits from life; sort them; when both play a part; instinct or learned behaviour | LIF4-033 instinct or learned |
| 37 | Life cycles of plants and animals | LIF4-040, 041, 042, 043, 044 | 5 | Pollination, seed forming, seeds travelling, germination; complete change or gradual growth in animal life cycles | LIF4-044 complete change or gradual growth |
| 38 | What happens when a 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 | LIF4-052 adapt or go extinct |
Totals: 158 lessons, 38 practice sets, 38 PP100s (banks of at least 50 items each, at least 5 per atom), 4 strand-test placeholders (after Topics 10, 16, 32, 38), 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 on 2 October (see "Checks run"); zero forward references.
- 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, including Topic 12's test of the design.
- Topic 12 needs Topic 4 (energy from giver to receiver, the carriers) for "spot the energy change", Topic 2 for the fair test, and Topic 11 for the criterion and constraint the build is tested against. After Physics is the earliest place all three hold.
- Topic 8 (waves) sits before Topic 22 (seismic waves need ENE4-040); Topic 21 (rock layers) sits before Topic 38 (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 (the 25 September ruling on the six per-family atoms). Topics 18 and 19 split them so no topic reaches seven.
- Energy resources follow Olivia's rule of surprising members first: wind, water, sunlight and plants (Topic 27) before the fuels everyone already calls "energy" (Topic 28), then the renewable-or-not sort on all seven (Topic 29).
- 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.
- No topic reaches seven lessons; none has fewer than three.
What changes: the folder gets grade4/topicNN_build/ per topic as each is built; Topic 11 is grade4/demo_criteria_constraints/ re-pointed as a topic folder (its code G4DEMO stays on the five live videos).
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 How to run 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 | 11 What a design must do, and what it must stay inside | the design chain's first three steps, built and reviewed on 2 October as the demo |
| SR4-023 Test the design against the rule | 12 How to build and test an energy changer | the energy changer is the first real build; the fair test (Topic 2) is the test |
| SR4-010 Construct a bar graph; SR4-011 Compare two sets of results; SR4-012 The result that doesn't fit | 25 Weather and 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 except Design and build (placeholders until Becky's format gate is passed); 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 23-24, STAAR 5.10A builds on them), weathering-erosion-deposition (Topic 20, feeds STAAR 5.10C landforms), circuits (Topics 9-10, feeds 5.8B), mixtures and "the mass holds" (Topics 14-15, feed 5.6B and 5.6C), food webs and producers-consumers-decomposers (Topic 35, feeds 5.12B), the Moon's shapes and Earth's spin (Topics 31-32, feed 5.9A).
- The strand-test placeholders fall after Topics 10, 16, 32 and 38; the format is the Grade 3 proposal of 30 September (30 items, 27 to pass, three protected forms), unchanged until Becky rules.
- The end-of-grade test samples all four science strands plus Design and build, with free-response items.
Checks run (2 October 2026, re-run on the assembled files)
- 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. Zero violations (script output in
grade4/records/ARCHITECTURE_CHECK_2026-10-02.txt). - Titles: every topic title fits "Here's everything we found out about ___".
- Topics of 7+: none. Topics of 2 or fewer: none.
What happens next
Topic 1 ("Why sliding things stop") gets its blueprint in the Grade 3 shape, then its lessons, quizzes, summary, practice, PP100 bank and scripts, straight through; the Grade 3 Forces golden pack is checked for reuse (FOR3-003's "a push or pull can slow or stop things" is friction's doorway). Topics follow in order. A lesson whose best teaching is genuinely uncertain comes to James as one question on the topic's decisions page; nothing else waits.