Raven puts the Sky Sorter logbook into a cabinet and clicks a small lock shut.
"A physical lock," she says. "Now let's talk about digital locks."
Rocket spins the dial. "This lock has three dials. How hard can it be to guess?"
Nova projects a counting chart onto the table. "Let's count the possible codes before you start guessing," she suggests.
Rocket groans. "This is going to be a lot of numbers, isn't it?"
Raven hands him a stack of index cards. "That is exactly the point."
A dial with the digits 0 to 9 has 10 choices.
Each new dial multiplies the number of possible codes by 10.
| Dials | How to count | Possible codes |
|---|---|---|
| 1 | 10 | 10 |
| 2 | 10 x 10 | 100 |
| 3 | 10 x 10 x 10 | ? |
| 4 | 10 x 10 x 10 x 10 | 10,000 |
Not everything needs a lock. Sort each card into one of three piles.
| Pile | Meaning |
|---|---|
| Public | Fine for anyone to see. |
| Trusted | Only for family or trusted adults. |
| Private | Kept to yourself and a grown-up who protects it, like a password. |
| Lab idea | True or false? |
|---|---|
| A lock on a cabinet is a physical security measure. | ? |
| A password on a device is a digital security measure. | ? |
| A code is still safe after you tell everyone what it is. | ? |
Great lab work. Tomorrow you weigh the trade-offs between sharing and protecting.