Topic 25 — Dangerous weather — blueprint (28 September 2026)
What I need from you: 5 decisions
Rain stays in millimeters here, as in Topic 22 — is that right?
L03's evidence is the class weather table (Topic 22's drawing) showing 40, 44 and 38 mm of rain on three days, and two items read a rain gauge (24 mm, 0 mm). Topic 23 was authored in inches. Whichever unit you rule on Topic 22's page, this topic's table and two items change with it.
My recommendation: millimeters, as Topic 22; one seam, fixed once.
Four harms taught — flood water, strong wind, lightning, deep snow. Leave hail and extreme heat out?
NGSS 3-ESS3-1's examples are floods, wind and lightning (levees, wind-resistant roofs, lightning rods); Texas and Arizona classrooms also meet hail and heat. Four harms keep L01's video at 150 words and every sort item to one key. Hail (dents cars, breaks windows) would be a fifth row in the table and a fifth harm in every option set.
My recommendation: four in Grade 3; hail and heat when EAR4-047 re-enters with several defences compared.
Keep "blizzard" as a snowstorm bringing deep snow only, so each weather brings one harm?
a real blizzard is snow plus strong wind, and a hurricane also floods the coast. Naming both harms would make "which harm does a blizzard bring?" have two keys. The lessons keep one harm per weather so every item has one answer; the tornado and the hurricane both bring strong wind (two weathers, one harm is fine).
My recommendation: keep one-to-one, with the full definition left for Grade 4.
Is a small flame on a barn roof, and no safety line, the right level for lightning?
the brief says describe, never dramatise, and a Grade 3 child should leave knowing people plan and build defences. Every damage drawn is mild (a wet floor, shingles on the lawn, a fallen fence, a blocked road, one small flame). No lesson says lightning can hurt a person, and there is no "go indoors" line — that is behaviour, not a design solution, and it is not an atom.
My recommendation: keep as written; if you want a safety line, it is one sentence at the end of L01 and I would rather you place it.
L03 says "what Harriet observed", never "evidence". Coin "evidence" here or leave it for Grade 4?
SR3-022's wording is "the best explanation for why" (Olivia, 28 Sep); Topic 16 gave the students "observation" and "idea about it". "Evidence" is the frameworks' word from Grade 4 (SC.4.N.1.6; NGSS 4-ESS). Coining it here costs one line in L03 and a term item.
My recommendation: leave it; "the one that fits everything you observed" is the rule, in words they already have.
Topic 25 at a glance — 3 lessons
| Lesson | Opens on | Format | |
|---|---|---|---|
| L01 | Weather can do damage | Here is Isadora at her window, in a town beside a river. | video + article |
| L02 | A defense holds the harm back | Here is Rupert at his front door. | video + article |
| L03 | Choose the best explanation | Here is Harriet in her yard on Tuesday morning. | video + article |
What this topic is, in five lines
Three short lessons, one per atom, closing the weather run of the Earth & Space strand. L01: dangerous weather brings a harm — flood water, strong wind, lightning or deep snow — and each harm does its own damage; one ordinary rainy afternoon shows the boundary. L02: nobody can stop the weather, but a defense holds one named harm back — sandbags and a levee, storm shutters and a windbreak, a lightning rod, a snow fence — and a defense works only when it holds back the harm that is coming (a levee is no defense against strong wind). L03: an explanation is an idea about why, and the best explanation is the one that fits everything you observed — worked on Harriet's flat fence and on the flooded school road with the class weather table as evidence, then asked bare.
The scenes are typical US places (a river town, the Florida coast, an Oklahoma farm, a Minnesota road), never a record storm; no one is hurt. Every drawn value sits on Topic 17's and Topic 22's scales. This topic's new register entries are the scene panel (before / after), the defense card, the evidence card, the explanation cards and the verdict mark; the weather table is Topic 22's, imported.
Applied without asking (rulings you have already given): hard PP100 items are typed (three of ten exemplars, all text entry); every attached question stands alone with its own drawing; no option bundles a verdict with a reason — every best-explanation item offers parallel single-sentence explanations under a drawn evidence card; every stem a positive question; colour in figures with cartoon / photo / svg kinds and a brief each; scene changes spoken with "let's", never an imperative; the intro ends on a ready line and a poll and names no lesson; three questions on the summary; a headache character in no item, a claim-maker once; fresh exemplars with a design-move inventory; the surprising member (rain that floods) before the everyday one (storm wind); the weather words of Topic 22 (wind FROM the west); "best explanation", never "sensible cause"; the no-fear line said once per lesson; one lesson per atom, three lessons.
Weather can do damage L01
Here is Isadora at her window, in a town beside a river.
It has rained for three days.
The river is higher than she has ever seen it.
Rain is just water.
Can it really do any damage?
Down the street, water is spreading onto the road.
Dangerous weather brings a harm: flood water, strong wind, lightning or deep snow.
Each harm does its own damage.
Three days of heavy rain bring flood water, and flood water soaks the ground floor of a house.
Most weather does no damage at all.
Video: the Day 1 panel becoming the Day 3 panel as the water rises; the wind streaks arriving and the tree falling; the bolt and the small flame; the snow piling around the car; the table building a row at a time — video and article.
Part 1 — EAR3-013 — Identify the damage a named weather hazard can do
Part 1q — quiz, 12 items
A defense holds the harm back L02
Here is Rupert at his front door.
The river is rising again.
Last spring, flood water came in under this door and soaked the whole floor.
Nobody can stop the rain.
So what can Rupert do?
His dad brings a pile of sandbags.
Nobody can stop the weather, but a defense can hold the harm back.
A wall of sandbags across the doorway holds back flood water, so the floor stays dry.
A defense works when it holds back the harm that is coming.
A levee cannot hold back the wind, so it is no defense against strong wind.
Video: the bags stacking row by row as the water rises; the levee with the river climbing its side; the shutters, the rod and the snow fence in turn; the streaks passing over the levee and the red cross — video and article.
Part 1 — EAR3-014 — Judge whether a design would reduce a weather hazard's damage, naming what it holds back
Part 1q — quiz, 13 items
Choose the best explanation L03
Here is Harriet in her yard on Tuesday morning.
The fence is lying flat on the grass.
It was standing yesterday.
Why did the fence fall down?
Her brother says a cow pushed it over.
Her mom says the wind blew it down.
An idea about why something happened is called an explanation.
The best explanation is the one that fits everything you observed.
Harriet saw branches all over the yard and heard the wind howl all night, so 'the wind blew it down' fits.
No cows live near the yard, so 'a cow pushed it over' does not fit.
Video: the evidence card's lines appearing one by one; the question appearing above the three cards; a red cross, a red cross, a green tick as each explanation is checked — video and article.
Part 1 — SR3-022 — Choose the best explanation for why something happened
Part 1q — quiz, 10 items
Language decisions
- The atoms' words: "dangerous weather" (not "hazard"), "harm", "damage", "flood", "hurricane", "tornado", "blizzard", "defense" (US spelling), "levee", "storm shutters", "lightning rod", "snow fence", "windbreak", "explanation", "best explanation". "Observation" is Topic 16's word, used not re-coined.
- One harm per weather, so every sort has one key: rain for days → flood water; a hurricane's wind or a tornado → strong wind (a hurricane also brings flood water, so it is never sorted to one harm); a thunderstorm → lightning; a blizzard → deep snow (decision 3).
- "Holds back" is the defense verb; the lightning rod alone "keeps lightning away from the roof" and "gives it a safe path to the ground".
- "Nobody can stop the rain / the weather" is said once per lesson and asked in the intro; every defense line names what people DO.
- Topic 22's weather words: "the wind howled from the west" (wind FROM a direction); rain in millimeters (decision 1); the table's words calm / breezy / windy.
- No "gravity", "force", "energy", "evidence" (decision 5), "cause", "sensible", "lift", "leak", "creep", "rage". "Spreads", "soaks", "tears off", "knocks down", "blocks", "strikes", "piles up".
- Openers vary: L01 "Here's Isadora…", L02 "Here's Rupert… The river is rising again.", L03 "Here's Harriet…"; contractions in scripts and headaches.
PP100 type sheet (TYPE_SHEET_ONLY; James's 28 Sep night ruling: hard items are typed)
Ten types, ten exemplars, two alone-types per atom and four pair types; seven four-option MCQs (easy and medium) and three typed hard items (the defense for a rising river; the harm storm shutters hold back; the harm an evidence card fits). Coverage table and design-move inventory in records/TYPES_G3T25.md.
Figures
48 figures: 39 svg (the scene pairs, the defense cards, the two tables, the evidence and explanation cards, the rule cards), 6 photos (a flooded street, a fallen tree, a snowed-in road, a levee, storm shutters, a fallen fence — every brief says MILD), 3 cartoons (Isadora at the window; Rupert and his dad with the sandbags; Harriet at the fence). Every figure has an IMAGE_BRIEFS entry and an IMAGE_KINDS entry; people and hands are never drawn as glyphs. Item figures carry no verdict mark and no chip; the blind comment lists what is drawn, never the answer.
Deliberately not taught
Hail and extreme heat (decision 2); a blizzard's wind and a hurricane's flooding (decision 3); why lightning strikes tall things; how a levee is built or how high; what to do in a storm (decision 4); the word "evidence" (decision 5); comparing two defences for one harm (EAR4-047); the design process itself (the SR family); why the wind pushes things over (Forces); reading the weather table (Topic 22, used not retaught).
This grade’s course architecture — open only if you want the whole map
Skill: course-build → atomise (architecture, step 6b gate) → write-like-james @ acc4fb6
Grade 3 Science — course architecture v3 (James's rulings of 25 September, plus Olivia Mullins's sequencing)
Read this in five minutes. Grade 3 Science is ONE course with a fixed order; nobody picks strands. It arranges the 183 Grade 3 atoms into four strands and forty-two 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.
Rulings recorded (James, 25 September 2026)
- Strand order: Physics, Matter, Earth & Space, Life. James: "I don't think it matters hugely … Happy to go with 1 Physics 2 Matter 3 Earth and space 4 Life. That works well." Strands may be intermingled later if a reason appears; none does yet.
- Grade 3 is one course. "We're not going to allow students to pick any strand … we need to structure Grade 3 as we think Grade 3 should be structured best." v1's line about students choosing strands was wrong and is gone.
- Topic 1 is the pilot. "That topic 1, I think, works as a good pilot."
- Small topics. "3 atoms is fine for testing. PP100s on quite granular stuff is absolutely fine … A 4-atom topic and a 5-atom topic is great. 9 is too many, really … if something's got 9 atoms, we should be considering splitting it." So sound, soil, fossils and natural resources each stand alone, and every v1 topic of nine or more was split (Card 2). Topics 1 and 2 keep 8 and 7 lessons because James approved Topic 1 as it stands and Topic 2 is one chain about speed; both are flagged as split candidates once their PP100 data arrives.
- Forces opens with Earth's pull and magnets, before the word "force" (Olivia Mullins call, 25 September; James: "I think I'll follow that"). Topics 3 and 4 teach the two non-touching pulls with no talk of forces; Topic 5 coins "force" on both of them and on the hand push together, so the hand push never becomes the whole category. Her two classroom misconceptions (Earth pulls only on your feet; "balanced" is a kind of force) are in the register and the lessons.
- States of matter start with air (Olivia): air takes up space → gases spread → liquids → solids → the sort.
Applied from the earlier rulings: four strands; Motion before Forces before Energy; Scientific Reasoning atoms taught inside the topics that use them; one intro video per strand and per topic, each teaching nothing; one atom, one lesson, both video and article; a summary video before every PP100; PP100 banks of at least fifty items tagged by depth of reasoning; the Forces topics reuse the golden pack; the language rules (Earth's pull, carriers not forms, no "leak" or "lift").
Card 1 — The strands and their order
The call: Physics → Matter → Earth & Space → Life, each with its own intro video and its own end-of-strand test.
| Strand | Topics | Atoms | Why it sits here |
|---|---|---|---|
| Physics | 1-15 | 64 | Motion first: what you can see, before the invisible cause. Energy last: "faster means more energy" needs speed. |
| Matter | 16-21 | 22 (+7 Scientific Reasoning) | Uses the measuring tools and feeds Earth's water cycle in Grade 4. |
| Earth & Space | 22-31 | 41 (+4 Scientific Reasoning) | Weather uses tables and graphs; "the Sun powers Earth" must precede food chains. |
| Life | 32-42 | 43 | Ends the year; leans on Space (the Sun), Forces (Earth's pull) and Matter (properties). |
Scientific Reasoning's 13 atoms are spread through Topics 1, 16, 17, 22, 23 and 25 (Card 4). Total 183 lessons.
Card 2 — The topics
The call: forty-two 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 | Where is it? Did it move? | MOT3-001, 002, 003, 004, 005, 006, 007, 008 (+ SR3-020, 021 inside L07/L08) | 8 | You say where something is with a landmark; moving means its position changed; motions can repeat |
| 2 | Fast and slow | MOT3-020, 021, 022, 023, 024, 025, 026 | 7 | Faster means farther in the same time, or the same distance in less time |
| 3 | Earth pulls things down | FOR3-021, 029, 030, 028, 022 (+ a closing lesson naming gravity) | 6 | Earth pulls every object, all the time, straight down, on every part of it, without touching; a strong enough pull can beat it; the pull's name is gravity (JM 28 Sep 2026; no word "force" yet) |
| 4 | Magnets | FOR3-023, 024, 025 | 3 | A magnet pulls steel without touching; two magnets pull or push; use a magnet to solve a problem (no word "force" yet) |
| 5 | What a force is | FOR3-012, 001, 008, 006 | 4 | Earth's pull, a magnet's pull and your push are all forces; push or pull; on one object; in one direction |
| 6 | Forces that touch, and forces that don't | FOR3-020, 027, 026 | 3 | Some forces act without touching: Earth, magnets, a rubbed balloon; most pushes touch |
| 7 | Pushes and pulls change things | FOR3-002, 003, 004, 005, 007 | 5 | A push or pull starts, stops, turns or squashes; you can test it |
| 8 | Strong or weak: drawing a force | FOR3-009, 010, 011 | 3 | A stronger push makes a bigger change; an arrow shows a force's direction and strength |
| 9 | Balanced forces | FOR3-040, 041, 042, 043, 045 | 5 | Several forces act at once; balanced forces leave motion as it is, still or steady |
| 10 | Unbalanced forces | FOR3-044, 046, 047 | 3 | Unbalanced forces speed up, slow down or turn |
| 11 | Energy: what has it, how it travels | ENE3-001, 002, 003, 004, 005, 034 | 6 | Energy makes things happen; light, sound and electricity carry it; faster means more |
| 12 | Sound | ENE3-030, 031, 032 | 3 | Sound comes from vibration and travels to your ear |
| 13 | Light: sources, straight lines, shadows | ENE3-010, 011, 012, 017 | 4 | Light comes from a source, travels straight, makes shadows, must reach the eye |
| 14 | Light bounces, bends or soaks in | ENE3-013, 014, 015, 016 | 4 | Reflection, refraction, absorption, sorted |
| 15 | Light and heat | ENE3-020, 021, 033 | 3 | Light-givers give heat; rubbing makes heat; light carries energy |
| Matter | ||||
| 16 | Describe it, sort it | SR3-001, 002, MAT3-001, 002, 003 | 5 | Observe with more than your eyes; describe an object by its properties; sort and order |
| 17 | Measuring tools | SR3-003, 004, 005, 006, 007 | 5 | Thermometer, scale, measuring jug; pick the right one; two groups can disagree |
| 18 | Which has more? | MAT3-004, 062, 005, 006 | 4 | More mass, more space, warmer, decided by a measurement; MAT3-062 "everything takes up space" (JM ruling on Olivia's comment, 28 Sep 2026) sits before the space comparison |
| 19 | Sinks, floats, sticks to a magnet: choosing materials | MAT3-007, 008, 060, 061 | 4 | Test a property, then pick the material for the job |
| 20 | Solids, liquids and gases | MAT3-063, 064, 065, 022, 023, 021, 020, 024 | 8 | Air first (Olivia's order): air is something you can feel; it is made of tiny pieces too small to see; so is every kind of matter; air takes up space; gases spread out to fill their space; liquids take their container's shape; solids keep theirs; then the sort with the awkward cases. MAT3-063, 064, 065 were added on 28 Sep 2026 (JM's rulings on Olivia's comments) before MAT3-022 in the chain; eight lessons is over JM's 3–6 size, so the Topic 20 build record (decision 1) proposes a split after MAT3-022 into "Air is something" (4) and "Solids, liquids and gases" (4), renumbering Matter to 16–22, Earth & Space 23–32, Life 33–43 — nothing after Topic 19 is authored, so the renumbering costs nothing now |
| 21 | Heating and cooling | MAT3-040, 041, 042, 043, 044, 045, 046 | 7 | Heating and cooling change the state but it is the same water (split candidate: melting/freezing vs evaporating/condensing) |
| Earth & Space | ||||
| 22 | Measuring the weather | EAR3-017, 018, 019, SR3-010, EAR3-020, SR3-011 | 6 | Three instruments, a weather diary, reading it back |
| 23 | Weather over a season, and far away | SR3-012, EAR3-022, 023, 021, 024 | 5 | A season's records make a chart; the chart predicts; other places differ |
| 24 | Volcanoes, earthquakes, landslides | EAR3-007, 010, 008, 011, 009, 012 | 6 | What each one is, then how it changes the land fast |
| 25 | Dangerous weather | EAR3-013, 014, SR3-022 | 3 | Weather can do damage; a defence holds it back; pick the sensible cause |
| 26 | Soil | EAR3-001, 002, 003, 004 | 4 | Soil is broken rock plus dead things |
| 27 | Fossils | EAR3-029, 030, 031, 032, 033 | 5 | A few dead things last as fossils and tell of the past |
| 28 | Using and conserving natural resources | EAR3-040, 041, 042, 043 | 4 | Everything you own started as a natural resource; some run short |
| 29 | The Sun | SPA3-001, 007, 002 | 3 | A huge glowing ball of gas; a star; the source of Earth's energy |
| 30 | The stars | SPA3-003, 004, 005, 006 | 4 | Stars differ; they look like dots because they are far; telescopes show more |
| 31 | The solar system | SPA3-010, 011, 012, 013, 014 | 5 | Earth orbits the Sun with seven other planets; the Moon orbits Earth |
| Life | ||||
| 32 | Alive or not | LIF3-001, 007, 008, 009, 002 | 5 | Living things grow, feed, move and make more; sort living from non-living |
| 33 | What living things need | LIF3-003, 004, 005, 006 | 4 | Food, water, air and a place that suits them |
| 34 | Backbone or no backbone | LIF3-010, 011, 070 | 3 | Grouping by shared features; vertebrates, invertebrates, arthropods |
| 35 | The five vertebrate groups | LIF3-015, 016, 017, 018, 019, 012 | 6 | Mammal, bird, reptile, amphibian, fish, then the sort |
| 36 | Eggs, body parts and senses | LIF3-013, 020, 027 | 3 | Egg-layers or live birth; body parts do survival jobs; animals sense, then respond |
| 37 | How plants make new plants | LIF3-071, 072, 014, 024 | 4 | Seeds, spores, the sort, the flower's job |
| 38 | Plant parts and their jobs | LIF3-021, 022, 023 | 3 | Roots, stem, leaves |
| 39 | Plants respond | LIF3-025, 026, 028 | 3 | Stems grow to the light, roots grow down; plants respond by growing, animals by moving |
| 40 | Life cycles and family likeness | LIF3-030, 031, 040, 041, 042 | 5 | Every life runs in a cycle; offspring take after their parents but differ |
| 41 | Food chains | LIF3-050, 051, 052 | 3 | Every food chain starts with the Sun; remove a link and the rest changes |
| 42 | Living together and coping with change | LIF3-060, 061, 062, 063 | 4 | Groups, places and seasons decide who survives |
Totals: 183 lessons, 42 practice sets, 42 PP100s (banks of at least 50 items each), 4 strand tests (after Topics 15, 21, 31, 42), 1 end-of-grade test.
Why this grouping
- Every prerequisite edge points backwards in this order. Checked atom by atom in the assembled files; no forward reference.
- Animal topics (33-35) and plant topics (36-38) are separate, as James asked; the plant-versus-animal response contrast (LIF3-028) closes Topic 38 because it needs both sides taught.
- Topics 3 and 4 teach Earth's pull and magnets without the word force; Topic 5 coins it on all three kinds (Olivia's sequence). Topic 8 carries the two force-arrow atoms so Topics 9 and 10 can draw balanced and unbalanced forces.
- Topic 24 puts "what a volcano is" straight before "volcanoes change the land fast", and the same for earthquakes and landslides: what it is, then what it does.
What changes: the folder gets grade3/topicNN_build/ per topic; Topic 1's blueprint is approved; Topic 1 is built first.
Card 3 — Topic 1 is the pilot (approved)
The call: pilot "Where is it? Did it move?" end to end — 8 lessons, an attached question per video, a ten-item quiz after each, mixed practice, summary video, PP100 — before any other topic starts.
- It is the first thing a Grade 3 student meets, so the whole format ladder gets tried where the stakes are lowest.
- It holds a fact, four sorts, two routines and a prediction. Every check type the course needs appears once.
- Its quiz items are drawings of everyday scenes, so the figure pipeline for young grades gets tested too.
- Topics 3 to 10 follow, reusing the golden Forces pack where its lessons match (push or pull, force on one object, strength, direction, more than one force, the balanced and unbalanced lessons).
Card 4 — Scientific Reasoning is taught where it is used
The call: each of the 13 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 |
|---|---|---|
| SR3-001 Observe with more than your eyes; SR3-002 Observation or idea about it? | 16 Describe it, sort it | describing an object's properties is observing |
| SR3-003 Read a thermometer; SR3-004 Measure mass with a scale; SR3-005 Measure the volume of a liquid; SR3-006 Pick the right measuring tool; SR3-007 Two groups, two different answers | 17 Measuring tools | the tools before "which has more?" uses them |
| SR3-010 Record results in a table; SR3-011 Find a value in a table | 22 Measuring the weather | the weather diary is the first table students fill and read back |
| SR3-012 Read a pictograph or bar graph | 23 Weather over a season | the graph before the graphing routine |
| SR3-020 Spot the pattern; SR3-021 Use the pattern to predict | 1 Where is it? Did it move? (inside L07 and L08) | the swing's repeat is the pattern |
| SR3-022 Choose the sensible cause | 25 Dangerous weather | first place students pick a cause for an event |
Card 5 — 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 3 tests are our own banks, seeded from released grade-5 items filtered to Grade 3 atoms.
- No state tests science before grade 5 (D1 ruling). The released STAAR, Florida SSA and AZSCI grade-5 forms give the style and difficulty; items tagged to Grade 3 atoms seed the banks.
- The strand tests fall after Topics 15, 21, 31 and 42.
- The end-of-grade test samples all four strands with free-response items.
What happens next
Topic 1 is built as the first interactive version for James: the topic intro (video script and article), eight lessons each as a video script with animation guidance and an article with figures, one attached question per video, a ten-item quiz per lesson, mixed practice, the summary video script and the PP100 bank. Topic 3 follows, reusing the golden pack.