SPACE ACADEMY · TRY, THINK, PLAY

Class 4: Time travellers

Connect clock hands, calendars and elapsed-time clues at the selected challenge level.

Try a quick challenge

Just a quick try. Not saved; no game rewards.

ExploreClocks and elapsed time

Use Isha's timed lab tasks. Find the finishing time.

Follow the lab work timelineScan35 minStart 10:45Finish: ?
  1. 12:20
  2. 10:20
  3. 10:10
  4. 11:20
Need a hint?

Follow each interval, regrouping a full hour of minutes when needed.

Answer & method
Answer D: 11:20

35 = 35 minutes. Count on from 10:45 to 11:20.

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ReasonClocks and elapsed time

Ravi follows the lab timeline. At what time will the work finish?

Follow the lab work timelineScan55 minPause35 minSort45 minStart 7:15Finish: ?
  1. 8:55
  2. 9:30
  3. 8:10
  4. 8:45
Need a hint?

Follow each interval, regrouping a full hour of minutes when needed.

Answer & method
Answer B: 9:30

55 + 35 + 45 = 135 minutes. Count on from 7:15 to 9:30.

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StretchClocks and elapsed time

Kabir starts a science show at 06:15. It lasts 1 hour 10 minutes. At what time does it end?

  1. 07:25
  2. 08:25
  3. 07:15
  4. 06:25
Need a hint?

Add the hours first, then the minutes. If the minutes pass 60, carry 1 hour.

Answer & method
Answer A: 07:25

06:15 plus 1 hour 10 minutes is 07:25.

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For grown-ups

Ideas to practise

  • Clocks and elapsed time. Separate hours and minutes. There are 60 minutes in one hour.
  • Calendars. Read the weekday headings. A week has seven days; count intervals, not both endpoints.

A game mission has 8 untimed questions. Only the game saves choices and hints. A finished mission earns one launch charge and participation towards the Survey telescope in Nebula Research Station. The chapter goal is 8 different questions in finished sets; hints and wrong answers count as participation, not mastery. Some craft systems link more than one chapter.

Choose a level

Explore

Foundations: read a representation and practise the underlying idea.

  • Find a start time, an end time or a duration
  • Change between hours, minutes, days and weeks
  • Count days between dates or find a return date
  • Find a missing interval on a timeline
  • Use a timetable with a waiting condition
  • Schedule an event on a calendar
Play Explore

Reason

Paper-style reasoning: connect clues, interpret a diagram or work backwards.

  • Add or subtract ages in years and months
  • Find a start time, an end time or a duration
  • Change between hours, minutes, days and weeks
  • Count days between dates or find a return date
  • Find a missing interval on a timeline
  • Use a timetable with a waiting condition
  • Schedule an event on a calendar
  • Correct a fast or slow station clock
Play Reason

Stretch

Higher-order practice: link conditions, test statements and avoid a tempting wrong method.

  • Add or subtract ages in years and months
  • Find a start time, an end time or a duration
  • Count days between dates or find a return date
  • Use a timetable with a waiting condition
  • Schedule an event on a calendar
  • Correct a fast or slow station clock
  • Find a missing interval on a timeline
Play Stretch

Levels change representations, clues and conditions, not just the numbers. These are practice formats, not validated exam-equivalent difficulty.

Using the feedback

Learning reports distinguish hinted answers from independent first choices. They consider up to 20 recent different, unhinted questions per skill and level, and wait for at least five before suggesting extra practice. Repeating the same question does not add evidence. Reports are practice evidence, not IQ scores, diagnoses, ranks or predictions of competition results.

Ask the learner to explain a drawing or check with objects too. Choose Explore or an earlier chapter when a step feels too large.

Sources & limits

The grade topics use SOF IMO Class 4 published topic syllabus as their primary reference. The SOF sample and CREST previous-year paper below informed representations and reasoning demands. Providers have different topic boundaries; their syllabi are not interchangeable.

Questions, diagrams, picture choices, hints and explanations are original Otterly work, not copied paper questions or publisher artwork. No Olympiad provider is affiliated with or endorses Space Academy. This is not complete exam preparation; follow classroom teaching and check the current official syllabus too. Independent educator review is still needed for difficulty and breadth.

Content and coverage notes. To report a confusing question, describe the grade, chapter, level and question on the contact page. Do not send children’s personal information.

Private, local saves

Game progress stays only in this browser, in three anonymous explorer slots. Clearing site data or closing a private session may remove it. Download a private backup from Help & saves; there is no cloud sync. The game checks saves before play and stops on save failures rather than pretending progress was saved.

These page examples never change a saved game. Game links carry question settings, not a learner’s answers. There are no names, school details, public profiles, chat, analytics or advertising SDKs in the game. Grown-up guidance · Privacy

Original Otterly practice, not an official exam. Game progress stays on this browser.