Skill: course-build → write-mcqs → design-check-sequence, write-explanation @ eed9456

Topic 2 — Fast and slow — the PP100's question types, one exemplar each

The gate this page is. James reviews ONE exemplar per type before any bank is generated (50 Decisions/A bank is reviewed as its question types first, one exemplar each.md). The blueprint's list of eight types was ruled on 28 September 2026 (type 5, which needed speed = distance ÷ time, was cut as too hard; the ranking type became a reorder item; "ten is a ceiling, not a target"). These eight exemplars are the only items in content/G3T02.py's PP100 list (TYPE_SHEET_ONLY = True, so the checker skips the bank-size sweep). Nothing here has been rejected before; nothing is held.

What every exemplar keeps to. Four options (the reorder item has four names), one complete statement per option, no option that joins a verdict to its reason, a positive stem of one or two sentences (three or more only on the hard item), no scene from a lesson or a lesson quiz (the inventory below), no item that needs a calculation, "you cannot tell from this" left to the L03 and L04 quizzes, US English, grade-3 words.

The eight types

#	Type — what the stem asks, what the four options are	Side	Tag	Exemplar
1	Four objects, each described at one moment; which one's position is changing right now. Options: the four objects (three still, one moving; the slow mover is the medium instance).	A (L01)	easy	PP-1
2	Four described motions; which one changed direction. Options: the four motions, three along a straight path and one with a turn. Medium instance: a drawn path from above with four marked points; at which point did the direction change.	A (L02)	easy	PP-2
3	A drawn table of four objects and how far each went in the same time; which is the fastest (or the slowest). Options: the four objects.	A (L03)	easy	PP-3
4	A drawn table of four runners and the time each took over the same distance; who is the fastest (or the slowest — the longer time is the slower one). Options: the four runners.	A (L04)	medium	PP-5
5	One object; which sentence tells you its speed. Options: four sentences about that object — a distance, a time, a position, a distance in each second.	B (L05)	easy	PP-4
6	A drawn table of four animals or vehicles and how far each went in the same time; tap them into order from fastest to slowest. Response: the four names as buttons, tapped in order (a REORDER item, ruled 28 Sep). Medium instance: rows out of speed order; two distances close together (78 m and 80 m).	B (L06)	medium	PP-6
7	One journey as the distances in each second (words, or a drawn road with a mark at each second and the question chip); what is happening to its speed. Options: speeding up / slowing down / the same speed / speeding up, then slowing down.	B (L07–L09)	medium	PP-7
8	A scene with the verdict fixed in the stem; why. Options: four single-statement reasons, one right and three real errors, always the positive form.	A or B by scene	hard	PP-8

Rows are in type-number order. The bank list itself runs easy → medium → hard, so in PP100 type 5's exemplar sits fourth (PP-4) and type 4's fifth (PP-5).

The exemplars, printed in full

Type 1 — PP-1 · atom MOT3-020 · easy

Stem: Which of these has a changing position right now?

a) a bike leaning on a wall
b) a book lying on a desk
c) a cat asleep on a chair
d) a ball rolling across the floor ← key

Why: A moving object is always changing its position. / The rolling ball is moving, so it is somewhere new each moment. / The bike, the book and the cat are all still, so their positions stay the same.

Design move: one moving thing among three still things, each named at one moment (L01's quiz asks the yes/no of ONE object; this asks the pick among four). Fresh against L01's marble, bus, clock hand, truck, leaf, girl, dog, parked car.

Type 2 — PP-2 · atom MOT3-021 · easy

Stem: Which of these moving things changed direction?

a) a skier slides straight down the slope
b) a train runs along a straight track
c) a boy runs to the wall and then runs back ← key
d) a marble rolls straight across the floor and stops

Why: Running to the wall, the boy went one way. / Running back, he went the other way, so he changed direction. / The skier, the train and the marble each kept going one way along a straight path. / Stopping is not turning.

Design move: one turn among three straight motions, with the two boundary cases from the lesson (stops; goes faster along a straight line) as distractors. Fresh against L02's gym ball, car at the corner, dog and tree, and the quiz's sled, cat, bird, girl and mailbox, kicked ball.

Type 3 — PP-3 · atom MOT3-022 · easy · fig `table_pp_four_toys`

Stem: Four wind-up toys ran for the same 10 seconds. Which toy is the fastest?

a) the robot
b) the mouse ← key
c) the crab
d) the penguin

Why: All four toys had the same 10 seconds. / The distances are 45 cm, 70 cm, 20 cm and 55 cm. / The mouse went 70 cm, the farthest in the same time, so the mouse is the fastest.

Design move: L03's rule on four rows instead of two (pick the biggest distance). Fresh against L03's frog and duck, snails, Priya and Zara, and the quiz's cars, ants, swimmers, planes, horse and dog, boats, beetles, trucks; fresh against L06's tables (vehicles, animals, swimmers, bugs).

Type 5 — PP-4 · atom MOT3-024 · easy

Stem: Which sentence tells you the ferry's speed?

a) The ferry went 500 m.
b) The ferry took 3 minutes.
c) The ferry is by the pier.
d) The ferry goes 5 m in each second. ← key

Why: Speed is how far something goes in each second. / "The ferry goes 5 m in each second" says exactly that. / 500 m is a distance, 3 minutes is a time, and by the pier is a position.

Design move: L05's "does this sentence tell you a speed?" turned from a yes/no on one sentence into a pick among a distance, a time, a position and a speed. Fresh against L05's bus and snail sentences and the summary's plane.

Type 4 — PP-5 · atom MOT3-023 · medium · fig `table_pp_four_children`

Stem: Four children each ran the same 20 m. Who is the slowest?

a) Amir
b) Bea
c) Cole ← key
d) Dina

Why: All four ran the same 20 m. / The times are 7, 5, 8 and 6 seconds. / Cole took 8 seconds, the longest time over the same distance. / A longer time over the same distance means slower, so Cole is the slowest.

Medium because: the ask is the slowest, so the student must hold "longer time means slower" against the pull of the biggest number meaning most; four rows instead of two.

Design move: L04's rule on four rows, asked for the slowest. Fresh against Ana and Ben, the boats, the snails, and the quiz's cars on a ramp, paper planes, worms, Sam and Ivy, Zoe and Tom, Maya and Eli, Rex and Bella, Omar and Lily.

Type 6 — PP-6 · atom MOT3-026 · medium · REORDER item · fig `table_pp_four_animals_order`

Stem: Four animals each moved for one minute. Tap the animals in order from fastest to slowest.

Response — the four names as buttons, tapped in order; the correct order:

the pony (400 m)
the sheep (80 m)
the pig (78 m)
the tortoise (5 m)

Why: All four had the same minute. / Line the distances up from biggest to smallest: 400 m, 80 m, 78 m, 5 m. / 80 m is a little more than 78 m, so the sheep comes before the pig. / So the order is pony, sheep, pig, tortoise.

Medium because: the rows are out of speed order and two distances are close (78 m and 80 m), so the student compares the numbers rather than reading the table top to bottom.

How it renders: the site builder's reorder renderer (added 28 Sep 2026 for this topic) shows the names shuffled as numbered buttons; the student taps them in order; the item is checked against the authored order; "Start again" clears the taps until the item is answered. The TimeBack export has no sequence type yet, so the exporter leaves a reorder item out of the bank file and notes it for David (see BUILD_RECORD, open items).

Design move: L06's routine, bare, in the platform's reorder form. Fresh against the snail, walker and cyclist and the quiz's vehicles, rabbit-hen-duck-goat, swimmers and bugs.

Type 7 — PP-7 · atom MOT3-028 (one of MOT3-025 / 028 / 029) · medium

Stem: A streetcar goes 9 m, then 6 m, then 3 m in three seconds. What is happening to the streetcar's speed?

a) speeding up
b) slowing down ← key
c) the same speed
d) speeding up, then slowing down

Why: In each second the streetcar goes 9 m, then 6 m, then 3 m. / Each second it goes less far than the second before. / So it is slowing down the whole time. / It never goes farther than the second before, so it is not speeding up at any point.

Medium because: the three classes are sorted in one item (the lessons ask one class at a time), and the fourth option names a real two-stage journey the student must rule out from the three numbers.

Design move: the mixed mastery quiz's three-way sort with a fourth, two-stage class added. Fresh against the scooter, the train, the bus coming in to its stop (10, 6, 2) and every quiz journey (skateboard, wagon, sled, truck, toy car, caterpillar, jogger, plane, race car, tortoise, beetle, boat).

Type 8 — PP-8 · atom MOT3-023 · hard

Stem: Two snails crossed the same tile, Pip in 30 seconds and Dot in 45 seconds. Why is Pip the faster snail?

a) Pip took less time over the same distance. ← key
b) Pip took more time over the same distance.
c) Pip crossed a longer distance.
d) Pip started crossing first.

Why: Both snails crossed the same tile, so the distance was the same. / Pip took 30 seconds and Dot took 45 seconds. / Less time over the same distance means faster. / So Pip is faster because Pip took less time.

Hard because: the verdict is fixed and the student must pick the reason from the rule, rejecting the longer-time reading (more time = faster), a false claim about what was compared (a longer distance) and an irrelevant one (who started first). No option bundles a verdict with a reason; the stem is a positive question.

Tag note (non-author review, 28 Sep): type 8 stays hard because James accepted the reason-item form as hard on Topic 1 (the ladybug, PP-49); if he would rather call "pick the reason from the rule" medium and keep hard for two-step cases, the bank generator tags accordingly — his call.

Design move: L04's rule with the verdict in the stem and reasons as options (the reason-item form from 10 Rules/An option never bundles a verdict with its reason.md). Fresh against every L04 scene; the L04 quiz's claim item (Omar) is the bare yes/no form on a different rule reading.

Reading notes for the review

Two types are side A only (1, 2), three are side A (3, 4, 8 by its scene), three are side B (5, 6, 7), so the cut after L04 stays possible without a type moving.
Types 3, 4 and 6 read a drawn table; the table gives the data, never the verdict (no order words, no winner).
"You cannot tell from this" is not a bank type: it stays in the L03 and L04 quizzes where the times or distances differ.
Once the types are approved, the bank is filled to about fifty from these types only, varying scene kind, numbers and nouns; the filled bank goes through the non-author question review and the blind read before it ships.