Year 42027

Year 4 OC Mathematical Thinking

Preparation for the NSW Opportunity Class placement test (sat in Year 4 for Year 5 entry): number reasoning, patterns, word problems and logic, spatial reasoning, data, and OC test technique.

24 interactive lessons · 27 exercise sets · free to read, no account needed

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  1. 1

    Place Value to 100,000 & Rounding

    Large numbers, rounding and estimation for quick checking.

  2. 2

    Four Operations: Fast & Accurate

    Fluent +, −, ×, ÷ with larger numbers under time pressure.

  3. 3

    Order of Operations & Number Sentences

    Evaluating and balancing multi-operation number sentences.

  4. 4

    Equivalent Fractions & Comparing

    Finding equivalent fractions and ordering fractions.

  5. 5

    Decimals: Tenths & Hundredths

    Decimal notation, money links and comparing decimals.

  6. 6

    Number Lines & Fractions: Jumps, Positions & Closest Numbers

    What one mark is worth, n jumps of a quarter turned into wholes and parts, placing a mixed number on a thirds or fifths line, which mixed number is closest to a whole, and how many jumps cover a distance.

  7. 7

    Number Sequences & Function Machines

    Finding rules, next terms and input-output machines.

  8. 8

    Shape & Growing Patterns

    Matchstick and tile patterns; predicting later terms.

  9. 9

    Multi-step Word Problems

    Breaking a problem into steps and keeping track of the goal.

  10. 10

    Working Backwards

    Starting from the answer and reversing the operations.

  11. 11

    Logic Puzzles & Deduction

    Who-owns-what grids, truth-tellers and elimination reasoning.

  12. 12

    Balance & Equivalence: Scales, Swaps & Made-up Money

    Which methods balance the scales (find the gap first), "3 pears weigh the same as 5 plums" bag comparisons, made-up money chains converted one link at a time, and picture balances solved by swapping.

  13. 13

    Rates, Work & Packing: Layers, Limits & Tournaments

    Which layer the last brick lands on (remainders), fewest bags under a mass limit (two roundings), two people sharing one job, everyone-plays-everyone tournaments, and steady money-box deposits with one unknown day.

  14. 14

    Units, Perimeter & Area Problems

    Reasoning problems mixing lengths, perimeters and areas.

  15. 15

    Time & Timetable Problems

    Elapsed time, schedules and timetable reading.

  16. 16

    Spatial Reasoning: Folding, Rotating & Views

    Nets, rotations, reflections and views of solids.

  17. 17

    2D Shapes: Classifying, Right Angles & Cutting

    Quadrilateral families and "all squares are rectangles" statements, counting right angles in figures made of lines, and what one straight cut does to a shape.

  18. 18

    Rotate, Reflect & Identical Shapes

    Quarter and half turns chosen from picture options, reflecting on a grid with grid references, turned shapes versus mirror images, and tiles rotated in a wall.

  19. 19

    Reading Scales: Thermometers, Jugs, Maps & Graphs

    Working out what one gap is worth, then reading thermometers with unlabelled ticks, jugs with unusual scales, map rulers in millimetres against a scale in centimetres, and graphs with a missing scale.

  20. 20

    3D Reasoning: Cube Stacks, Hidden Faces & Tallest Stack

    Counting cubes you cannot see, faces hidden by glued joins (2 per join), faces uncovered when a solid is broken apart, rebuilding from loose cubes, and the tallest stack three blocks can make.

  21. 21

    Area & Volume: Scaling, Shared Fractions & Displacement

    Area on a grid with half squares, what doubling every side does to area (× 4) and volume (× 8), matching shaded areas across two squares cut into different pieces, water displaced by sinking blocks, and cut-and-rearrange invariance.

  22. 22

    Graphs, Tables & Averages

    Reading complex graphs and simple averages in test questions.

  23. 23

    Chance: Certain, Likely & Equally Likely

    Chance words as counting words: boxes of discs, "blue or not blue", numbered counters with boundary numbers, spinners with unequal sectors, and changing a bag so two outcomes become equally likely.

  24. 24

    Multiple-Choice Speed & Elimination

    Time budgeting, elimination and educated guessing for OC format.

  25. 25

    Mathematical Reasoning Sample Test 1

    Full-length 35-question, 40-minute Mathematical Reasoning paper in the official format: five options, every strand shuffled, 20 questions with a figure, no calculator.

    🧩 Lesson🎬 Video📝 Quiz
  26. 26

    Mathematical Reasoning Sample Test 2

    Second full-length 35-question, 40-minute Mathematical Reasoning paper: different item shapes across every strand, 19 questions with a figure, answers balanced across A–E.

    🧩 Lesson🎬 Video📝 Quiz
  27. 27

    Mathematical Reasoning Sample Test 3

    Third full-length 35-question, 40-minute Mathematical Reasoning paper: a leap-year date, a picture balance, a missing-scale graph, cube rebuilding and more, 19 questions with a figure.

    🧩 Lesson🎬 Video📝 Quiz