Mathematics K–6 · Years 1–2

Half past and quarter past on a geared clock

Measurement and space

Practical, model not builtLow risk

This site has no interactive model of its own. Where a step or a material names a Concept Studio model, simulation or tool, it has not been built; an external simulation a step names (for example PhET) is not part of this site.

The idea

The minute hand and the hour hand move together: while the minute hand travels half way round, the hour hand moves half way from one number to the next.

What you need

a geared demonstration clock (turning the minute hand moves the hour hand)
a paper plate clock with two card hands on a split pin for each child
a strip of 12 time cards: o'clock, half past and quarter past times

How to do it

Set the geared clock to 3 o'clock. Turn the minute hand slowly once round and watch the hour hand creep to 4. Say what a whole hour looks like on each hand.
Set 3 o'clock again. Turn the minute hand half way round to the 6. Look at where the hour hand sits: half way between 3 and 4. Say half past 3.
Turn a quarter turn more to the 9. Say quarter to 4 and describe the hour hand position. Return to 3 o'clock and stop at the 3 for quarter past 3.
Each child shows the times on the cards on the paper-plate clock, placing the hour hand between numbers where it belongs, and a partner checks against the geared clock.
Read the classroom clock at the start and end of a lesson and say the times using o'clock, half past and quarter past.

What you should see

On the geared clock one full turn of the minute hand moves the hour hand exactly one number. At half past 3 the hour hand is half way between 3 and 4, and at quarter past 3 it is a quarter of the way. An hour hand placed straight on the 3 for half past 3 does not match the geared clock, which is how a partner checks it. On the paper-plate clocks every half past and quarter past time has the hour hand between two numerals, as on the geared clock.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

The hour hand points straight at a number until the next hour begins.
Half past means the minute hand points at the 6 and the hour hand is still on the hour.

Safety card

Low riskLearners carry it out

Hazards

split pins have sharp ends

Controls

an adult fits the split pins and folds the ends flat

Note

No chemicals or heat are used, so the NSW Department of Education Chemical Safety in Schools package is not needed; ordinary classroom supervision under the school's usual risk management.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Mathematics K-10 Syllabus (2022), NSW Education Standards AuthorityMA1-NSM-02 MAO-WM-01
Australian Curriculum v9AC9M2M04

Sources

The pages the author read to write this activity.

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