Week 03 · Lock and Key
Monday
Meet the lock and key
// A key's shape lifts the pins just right
⏱ about 15 min
Monday: Meet the Lock and Key
Rocket rattles a padlock on an old toolbox. It stays shut.
"Why will it not open for me?" Rocket asks.
Raven holds up a small key with a bumpy edge.
"What do you notice about the edge?" she asks.
Nova glows a view inside the lock.
"Would you like a hint? The bumps have a job," she says.
Where locks live
Locks keep doors, boxes, bikes and diaries shut.
A lock is a machine with a job: stay shut.
Only the right key can open it.
People have used locks and keys for about four thousand years.
The parts
| Part | What it does |
|---|---|
| Lock body | Holds the pins and springs inside |
| Keyhole | The slot where the key slides in |
| Key | A flat piece with a bumpy edge |
| Pins | Tiny rods inside that block the lock |
A key is flat with a bumpy, jagged edge.
The edge is cut in a special pattern.
That pattern fits one lock.
LOCK PARTS
- Read the question.
- Tap your answer.
What slides into the keyhole?
What is hidden inside the lock body?
What does a key's edge look like?
What is a lock's job?
Read the parts table and the story.
| Sentence | True or false? |
|---|---|
| A lock is a machine. | ? |
| Any key opens any lock. | ? |
| A key has a bumpy edge. | ? |
| People have used locks for a very long time. | ? |
WHY THIS EXERCISENaming the parts helps you see how they work together.
Try it
Ask a grown-up to show you a house key.
Look at the bumpy edge. Count the bumps.
Look at a second key. Is the pattern the same?
Look at the bumpy edge. Count the bumps.
Look at a second key. Is the pattern the same?
Safety first
Only hold keys a grown-up hands you.
Give every key back when you finish.
Keys stay out of mouths.
Give every key back when you finish.
Keys stay out of mouths.
STORY CHECK
- Read the question.
- Tap your answer.
What did Rocket rattle?
What did Nova say has a job?
Draw a key. Make the bumpy edge big.
You met the lock and its parts. Great noticing!
Tomorrow we find out what the bumps do inside.