Year 3 and 4 · OC Thinking Skills · Updated October 2026

Logic puzzles for Year 3 and 4: how to teach them for the OC test

Logic questions give your child a few clues and ask them to work out something that is not said directly: who is third, which day, who owns what. Children who do well are rarely the fastest thinkers. They are the ones who write the clues down instead of juggling them in their head.

Why logic matters in the OC test

The Thinking Skills section of the OC test has 30 questions in 30 minutes, and logic puzzles are one of its three main skills, next to critical thinking and problem solving. A logic puzzle often looks long, but once the clues are on paper it is usually quick. That makes it a place where good habits turn straight into marks.

Students get paper for working out in the test, so practising with a pencil at home is exactly right.

The draw-it method

1. Read the question line first. Who is shortest? Which day? Knowing the goal tells your child which clue to start with.
2. Draw the shape of the answer. A line for ordering, a grid for matching, the seven days for a calendar puzzle.
3. Start with the surest clue. "Gus learns the piano" goes in straight away. "Finn does not learn the violin" waits.
4. Cross out, do not guess. Each "not" clue removes a box. When only one box is left, that is the answer.
5. Check every clue at the end. Run down the list and tick each one against the drawing.

Four puzzle types with worked answers

These are written by us for practice and are not from any real test or from our free check. Give your child up to two minutes each and a pencil.

1. Ordering

Taller or shorter, before or after, left or right. Draw a vertical line and place each name as the clues arrive. If a clue cannot be placed yet, skip it and come back.

2. If-then rules

"If A, then B" only works one way. A powerful move for Year 4 is to work backwards: if B did not happen, A cannot have happened either.

3. Matching with a grid

Names down the side, choices across the top. A tick means yes, a cross means no. Each row and each column has exactly one tick.

4. Days of the week

Write the days in a circle, because Sunday is next to Monday. Many children forget that the week wraps around.

Common mistakes at this age

• Reading "not" too fast. "Finn does not learn the violin" becomes "Finn learns the violin" in a hurry. Ask your child to underline every "not".
• Stopping at the first possible answer. If two answers fit the clues, the puzzle wants "cannot be worked out", or a clue has been missed.
• Using outside ideas. "Girls are usually shorter" has no place in a puzzle. Only the clues count.
• Mixing up directions. Agree at home that "left" means the left of the page, and draw an arrow.

Logic games to play at home

Ten minutes a few times a week builds the habit better than a long session on Sunday. Ideas that need nothing you do not already have:

• Toy line-up. Line up four toys and give two or three clues ("the bear is before the car"). Your child builds the line, then makes up clues for you.
• Who has what. Hide three objects in three cups, give "not" clues, and let your child draw the grid.
• Calendar riddles. "My birthday is two days after the day before Thursday. Which day is it?"
• Swap roles. Children learn most when they write a puzzle for a parent and check that it has only one answer.

Once these feel easy, add a timer: one minute per puzzle, the same pace as the test. For the other two skills, see our page on critical thinking questions and the overview of Thinking Skills question types. For a weekly timetable, follow the 6-month OC preparation plan.