SPACE ACADEMY · TRY, THINK, PLAY

Class 1: Number detectives

Translate representations, use place value and solve constrained number clues.

Play missionChapters

Try a quick challenge

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

ExplorePlace value

Neel's crate holds rods and cubes. Count them all. What number is it?

Neel's crateTENSONES
  1. 65
  2. 56
  3. 55
  4. 10
Need a hint?

Count tens first, then ones, and apply the pictured change.

Answer & method
Answer C: 55

5 tens and 5 ones make 55.

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ReasonPlace value

Which number is 9 tens 2 ones?

  1. 29
  2. 11
  3. 92
  4. 82
Need a hint?

Write the tens digit first, then the ones digit.

Answer & method
Answer C: 92

9 tens is 90 and 2 ones is 2, so the number is 92.

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StretchComparing quantities

Which of these numbers is the smallest?

  1. 87
  2. 84
  3. 30
  4. 85
Need a hint?

Compare the tens digits first, then the ones.

Answer & method
Answer C: 30

In order the numbers are 30, 84, 85, 87, so the smallest is 30.

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For grown-ups

Ideas to practise

  • Place value. A digit has a different value in each position. Count the places from the right.
  • Number patterns. Look for the same change between neighbouring numbers.
  • Building numbers. Combine the place-value parts, including any zero places.
  • Comparing quantities. Compare the values, not the size or spacing of their pictures.

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 Control core in Mars Rover Rescue. 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.

  • Read and change a base-ten load
  • Read an equal-jump number line
  • Build a number from digit cards
  • Count a pictured group and choose its expanded form
  • Choose the number line with the stated jumps
  • Match a number with its number name
  • Split a number into tens and ones
Play Explore

Reason

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

  • Read an equal-jump number line
  • Build a number from digit cards
  • Move on a hundred-chart piece
  • Count a pictured group and choose its expanded form
  • Choose the number line with the stated jumps
  • Split a number into tens and ones
  • Find the greatest or smallest number
Play Reason

Stretch

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

  • Read and change a base-ten load
  • Read an equal-jump number line
  • Build a number from digit cards
  • Move on a hundred-chart piece
  • Count a pictured group and choose its expanded form
  • Choose the number line with the stated jumps
  • Match a number with its number name
  • Split a number into tens and ones
  • Find the greatest or smallest number
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 1 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.

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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.