P6 General Studies | The Solar System and Space Exploration Lesson-Prep Guide (for tutors) — 45-minute flow, teaching script, common errors

2026-11-15

Tutor lesson-prep guides · Primary General Studies

Students can chant eight planet names, yet cannot say why Earth takes one year and Jupiter twelve. This lesson turns the name list into a diagram you can calculate with.

Objectives — By the end of the lesson students can: (1) name the eight planets in order of distance from the Sun and state that Earth is third; (2) use 365 Earth days as the unit to give Jupiter about 12 years and Saturn about 29 years, and explain that a longer orbit plus a slower speed makes the year longer; (3) divide 150 million km by the speed of light to get 500 seconds, that is 8 minutes 20 seconds; (4) build a scale model in which Earth is 1 cm wide, the Sun is 109 cm, and Earth sits 117.7 m from it.

01 Prerequisites (3-minute check)

If any of these fails, fix it before the lesson starts.

Skill	Quick check	Pass mark
Multiplication	Work out 12742 times 109	Answer 1388878
Time conversion	Change 500 seconds into minutes and seconds	Answer 8 min 20 s
Large numbers	Write 150 million km as digits	Answer 150000000 km
Ordering	Say which planet comes third	Answer the third one

02 Lesson flow (45 minutes)

Time	Stage	Tutor does	Student does
0-6 min	Entry check	Ask the multiplication, the 500-second conversion and the digit form of 150 million; keep answers on the board	Answer orally and write the numbers down
6-15 min	Planet order	Lay out the eight planets from the Sun outward and mark the asteroid belt that separates rocky from gas planets	Order them once and point out that Earth is third
15-24 min	Orbital periods	Use 365 days as the unit: Jupiter is 4380 days, about 12 years; Saturn about 29 years	Convert Mars at 687 days into Earth years
24-33 min	Light speed and distance	Divide 150000000 km by 300000 km per second to reach 500 seconds	Say 500 seconds as minutes and seconds
33-41 min	Scale model	Make Earth 1 cm wide, so the Sun is 109 cm and the distance is 117.7 m; the Moon sits 30.2 cm away	Write all three model numbers on paper
41-45 min	Exit check	Mark the three questions at once and name the error type for each student	Say which type of error was made

03 Teaching script (read it out)

Scene 1: Act one: order the planets from the Sun, not from Earth

Write the Sun at the far left of the board, then the planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Earth is third, not first. The inner four are rocky, small and dense; then comes the asteroid belt; then the four gas and ice giants, which are large and low in density. So the memory hook is a structure, not a chant: four small inside, a belt of rubble, four large outside.

Where does Earth sit in the order, and what kind of planets lie beyond it?

Scene 2: Act two: the further from the Sun, the longer the year

A year is simply one full orbit. Earth orbits in 365 days and we call that a year. Jupiter is far out and travels slowly, so one orbit takes 11.86 Earth years, about 12. Saturn needs 29.46 years, close to 30. Why? The path is longer and the speed is lower, and both effects push the same way. Compare on one scale: Earth 1 year, Mars 1.88 years, Jupiter 12 years, Saturn 29 years.

About how many Earth years does Jupiter take for one orbit, and why is it so much longer?

Scene 3: Act three: light speed turns distance into time

Earth and the Sun are on average 150 million km apart. Light covers 300000 km each second. Divide: 150000000 divided by 300000 is 500, so sunlight needs 500 seconds, which is 8 minutes 20 seconds. The Sun you see now is the Sun of 8 minutes ago. The same trick builds a model: treat Earth as 1 cm wide, and the Sun becomes 109 cm, while the distance is 11772.1 Earth diameters, that is 117.7 m. The real solar system is mostly empty space.

How many seconds does sunlight take, and how far apart are Earth and the Sun in your model?

04 Question types and worked steps

Type	Example	Steps	Answer
Planet order	Which planet is third from the Sun	Count outward from the Sun, not from Earth	Earth, third
Orbital period	Mars takes 687 days; how many Earth years is that	Divide by 365.25 and keep two decimals	About 1.88 Earth years
Light travel time	How many seconds does sunlight need	Divide distance by light speed: 150000000 by 300000	500 seconds, that is 8 min 20 s
Scale model	With Earth at 1 cm, how far away is the Sun	Find the ratio to Earth diameter, then convert cm to m	11772.1 cm, that is 117.7 m

Sanity check (teach this): Three checks: (1) count planets outward from the Sun, never from Earth; (2) compare years in one unit only, so never mix a year with a day; (3) light time is distance divided by speed, so keep km with km per second and the answer is in seconds.

05 Independent practice (3 questions)

Question	Answer	What to watch
Of Mercury, Venus, Earth and Mars, which is furthest from the Sun?	Mars	Counted outward from the Sun instead of recalling
Jupiter takes about 11.86 Earth years per orbit. Roughly how many days is that, using 365 days a year?	About 4330 days	Multiplied by 365 rather than 24, and the answer is in the right order of magnitude
With Earth at 1 cm, the Moon 384400 km away is how many cm in the model?	About 30.2 cm	Divided by 12742 first, then converted units

06 Common mistakes and what to say

Mistake	Student writes	Say this
Counting planets from Earth	Saying Earth is the first planet	The count starts at the Sun: Mercury first, Earth third. Draw the Sun at the left before counting.
Confusing rotation with revolution	Saying a day on Earth is 365 hours	One rotation is 24 hours, one orbit is 365 days. Keep the two numbers apart.
Dividing light time the wrong way	Working out 300000 divided by 150000000	Distance goes on top, light speed underneath, giving 500 seconds; reversed you get 0.002 and the unit stops making sense.
Forgetting units in the model	Saying the model is 11772.1 m wide	11772.1 is centimetres; divide by 100 to get 117.7 m, which fits a sports field, not a corridor.

07 Homework (paper, section and question numbers)

P6 General Studies Paper 1, Earth and Space section — Section C, questions 1 to 3

08 Exit check (last 5 minutes)

Question	Answer	Decision
Which number planet is Earth?	Third	Wrong: reteach act one, counting from the Sun
How many Earth years is Mars at 687 days?	About 1.88 Earth years	Wrong: reteach act two, converting periods
How many seconds does sunlight take, and what is that in minutes?	500 seconds, that is 8 min 20 s	Wrong: reteach act three, distance over speed

09 Tutor FAQ

Which year level is this for?

Hong Kong primary General Studies covers the solar system and space at P6, including comparing orbital periods. The P5 Earth, Moon and Sun topic is the prerequisite, so revise rotation against revolution first if it is missing.

Is 45 minutes enough?

Yes, but keep eight minutes for the scale model. Students stall on turning 11772.1 cm into metres, so write the division by 100 on the board rather than saying it aloud.

Is there a practice paper?

Yes. The homework row links to the P6 General Studies paper on this site with the section and question numbers, and the page carries an answer version.

Find a tutor — free Tutor Registration →

A TutorZone lesson-prep guide. Written by the TutorZone team; questions and lesson flow are original and are not taken from any school or publisher material.