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
If both statements are true, what can you conclude?
If something is a quorp, then it is round.
The mystery thing is not round.
- A: The mystery thing is not a quorp. (the answer)
- B: The mystery thing is a quorp.
- C: We can't tell whether it is a quorp.
- D: The mystery thing is round.
Why: Every quorp is round. The mystery thing is not round, so it can't be a quorp.
Your turn
Your turn 1 of 3
Who is the lightest?
Jay is lighter than Nora.
Hugo is heavier than Nora.
Kai is lighter than Dev.
Hugo is lighter than Kai.
Your turn 2 of 3
Who is the second tallest?
Omar is taller than Lena.
Ana is taller than Omar.
Cleo is shorter than Hugo.
Cleo is taller than Ana.
Your turn 3 of 3
These are made-up words. If both statements are true, which must also be true?
No wumps are blips.
All glorps are blips.
Keep practicing
Grown-ups: Spot "if-then" reasoning in ads and the news together. Parent guide
Next lesson: Reading charts and tables