Welcome to the advanced levels: Previously, the villagers in Lambda Village got the “Plus 1” feature and the “Minus 1” feature back.
They were able to reproduce each feature using a lunchbox.
Looking for some other page?
However, they still haven’t gotten the “Repeat” feature back. They need to reproduce this using a lunchbox to get it back.
In case you forgot about the “Repeat” feature , let’s do a quick review.
Take a look at this mathbox and try pressing Run :
The result is . Because there’s next to , it repeats four times.
(This is still a review) For the villagers in Lambda Village, the “Repeat” feature was necessary to do additions and subtractions of large numbers.
Example (from Beginner 2): If you don’t use the “Repeat” feature , and wanted to calculate , you need to use ten times.
However: As the number gets large, we might make a mistake on the number of ’s to use. In such cases, we won’t get the correct results.
On the other hand: If you use the “Repeat” feature , you can calculate as follows. You won’t make a mistake on the number of ’s to use.
By using the “Repeat” feature , you’ll always use the correct number of ’s or ’s. You can be confident that your additions and subtractions are accurate.
This is why the “Repeat” feature was absolutely necessary for the villagers in Lambda Village.
The villagers have been trying hard to reproduce the “Repeat” feature using a lunchbox.
However, looks like it’s not going well for them.
Hmm… no matter how much I try, we can’t think of a way to reproduce the “Repeat” feature using a lunchbox.
Saya, do you have any good ideas?
I have no idea either…
Oh no. If Saya can’t figure it out, we’re doomed!
But luckily for them, Minion seems to be willing to offer some help.
Hey guys, it looks like you’re struggling. Do you want some hint?
Oh, thank you, Minion. Please, give us a hint!
Sure. First, let’s talk about the “Conditional” feature .
The “Conditional” feature ? What’s that?
Take a look at this mathbox:
What’s this?
It looks like a traffic signal …
First: You can fill each of , , and with any number.
The numbers could be all the same or all different.
Here’s an example. I used:
Next: Before I explain what means, let’s run this mathbox and see what happens.
Try pressing Run .
It became .
Let me explain why.
Here’s how the “Conditional” feature works.
First: It checks if the number in the bottom section is or not.
In this case, the number in the bottom section is .
Yes. And this is what happens next:
I see—that’s why it becomes .
I’ll show you another example. This one’s going to be a Yes / No quiz.
Take a look at this mathbox:
Question: If we run it, will it become like this?
It’s okay if you have no idea.
Just guess!