SPACE ACADEMY · TRY, THINK, PLAY

Class 5: Space supplies

Use pictured values and price boards to compare purchases, change and budgets.

Try a quick challenge

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

ExploreMoney and change

The supply board below lists prices. What is the total cost of 1 star map and 1 signal flare?

Star mapRs 18.00Signal flareRs 11.00Solar panelRs 20.00Repair kitRs 32.00
  1. Rs 29.00
  2. Rs 49.00
  3. Rs 11.00
  4. Rs 18.00
Need a hint?

Find each item's price on the board, then add them.

Answer & method
Answer A: Rs 29.00

Rs 18.00 + Rs 11.00 = Rs 29.00.

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ReasonMoney and change

The receipt below shows every item's price and the total paid. What is the missing price for the repair kit?

Oxygen tankRs 2.16Signal flareRs 2.21Solar panelRs 7.12Repair kit?TotalRs 14.25
  1. Rs 14.25
  2. Rs 11.49
  3. Rs 2.76
  4. Rs 12.09
Need a hint?

Add up every known price, then subtract that sum from the total.

Answer & method
Answer C: Rs 2.76

Rs 14.25 - (Rs 2.16 + Rs 2.21 + Rs 7.12) = Rs 2.76.

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StretchMoney and change

A solar sail is priced at Rs 300. It has 50% off, then an extra 50% off the new price. What is the final price?

solar sailRs 30050% OFF50% OFF
  1. Rs 0
  2. Rs 225
  3. Rs 75
  4. Rs 150
Need a hint?

Apply the first discount to the price, then apply the second discount to that new, smaller price -- not to the original price.

Answer & method
Answer C: Rs 75

Rs 300 with 50% off is Rs 150; Rs 150 with 50% off is Rs 75.

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For grown-ups

Ideas to practise

  • Money and change. Find the total cost first, then subtract it from the amount paid.

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 Science pod in Galaxy Command. 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.

  • Total a bundle of purchases from a price board
  • Apply or reverse a discount on a price
  • Find a missing price on a receipt
  • Compare packs to find the best value
Play Explore

Reason

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

  • Total a bundle of purchases from a price board
  • Apply or reverse a discount on a price
  • Compare packs to find the best value
  • Choose a purchase that meets a budget condition
  • Find a missing price on a receipt
Play Reason

Stretch

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

  • Choose a purchase that meets a budget condition
  • Apply or reverse a discount on a price
  • Compare packs to find the best value
  • Total a bundle of purchases from a price board
  • Find a missing price on a receipt
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 5 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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Original Otterly practice, not an official exam. Game progress stays on this browser.