Logic clues
Strategy card
Valid reasoning follows the form, not the topic.
- Step 1: Translate statements into a simple form (If P then Q).
- Step 2: Know the valid moves: P → Q and P gives Q; P → Q and not Q gives not P.
- Step 3: Watch for traps: Q does not prove P; not P does not prove not Q.
- Step 4: Ignore whether the made-up facts sound real; just follow the logic.
Tip: Swapping in nonsense words helps you focus on the form.
Worked example
In a secret code, LAMP is written as JYKN. How is DESK written in the same code?
- A: CDRJ
- B: ABPH
- C: BCQI (the answer)
- D: FGUM
- E: IQCB
Why: Each letter moves 2 earlier in the alphabet (L → J). So DESK becomes BCQI.
Your turn
Your turn 1 of 3
Who is the shortest?
Ella is taller than Pia.
Ella is shorter than Hugo.
Cleo is taller than Hugo.
Pia is taller than Dev.
Your turn 2 of 3
Who is the second tallest?
Ben is shorter than Ella.
Dev is taller than Ella.
Milo is shorter than Ben.
Kai is shorter than Milo.
Your turn 3 of 3
These are made-up words. If both statements are true, which must also be true?
All trells are zorns.
All zorns are mivs.
Keep practicing
Grown-ups: Spot "if-then" reasoning in ads and the news together. Parent guide
Next lesson: Reading charts and tables