Concept 7 of 8
Order the Steps: When Two Orders Both Look Right
Today's big idea
For a loose pair, ask which one needs what the other one produces.
Order the steps so each one's result is ready before the step that needs it.
How it works
👀 What's going on?
Some jumbled lists have an obvious order. Others have two orders that both sound perfectly sensible until you test them, and testing is what separates a guess from an answer.
💡 Here's the trick
Look at the five steps above. Writing the letter clearly comes first and posting it clearly comes last. In between, addressing the envelope and sticking the stamp could go either way. Test each one by asking what it needs, and the envelope has to exist and be sealed before anything is written on it.
🪄 How to do it
- 1.Place the steps you are sure of, as the panel above fixes the first step and the last.
- 2.For each step still loose, ask what has to exist before it can happen.
- 3.Put your order back through the list to check nothing depends on a later step.
✍️ Try it
Order Illness, Recovery, Doctor and Medicine. Then order Tree, Seed, Sapling and Plant.
The illness has to come first, then the doctor, the medicine and Recovery last. For the plant, nothing precedes the Seed, which is planted, becomes a sapling and finally a tree.
⚠️ Watch out
You might be thinking two steps that could swap means the puzzle has two answers. It almost never does. One of them needs something the other one produces, and finding that settles it.
🌟 Why this matters
Assembly instructions and cooking methods are full of steps that look swappable and are not. Testing what each step needs is what stops you taking something apart again.
Exam tip: Check your finished order forwards once, because a wrong pair shows up immediately.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“Put in order: 1. Butterfly 2. Egg 3. Caterpillar 4. Chrysalis”
- 1
Fix the certain start
Everything begins from the egg.
- 2
Follow the life cycle
Egg hatches to a caterpillar, which forms a chrysalis.
- 3
Read it back
Egg, caterpillar, chrysalis, butterfly.
- 4
Answer ✓
2, 3, 4, 1
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Ask what each loose step needs before you place it.
ORDER TESTER · ROUND 1 OF 3
Step 1 · two steps look swappable. What settles them?
Quick check
✅ VERIFICATION
Put in order: 1. Rain 2. Cloud 3. Evaporation 4. Water in the sea
⚡ Finish the activity above first to answer.
Keep going!
Up next: Venn Diagrams
The middle counts in both.