How to stop an alien invasion using proportions

Okay, aliens have just landed on earth and they'll take it over if we don't teach them about proportions.

First, they wanted to know how to find a unit rate.

~ example: three dinner rolls cost 99 cents.
- Here's one way of doing this:

~ seven identical objects have a mass of 14kg.

then they wanted to know how to get other numbers other then one.

~ example: Delia was payed $35 for 5 h of babysitting. How much should she receive in 3 h?

The last thing they wanted to know was how to find a missing number.
~ example: Determine the missing numbers.
- 60km/3h = ?km/6h
This is how to do it: 3h x 2= 6h so 60km x 2=120km.
- $3/4cans = $15/?cans
All you have to do is: $3 x 5=$15 so 4cans x 5=20cans.

You need to remember what you do to one side you have to do to the other side.

It's good because after they learned everything they decided not to take over earth. Crazy aliens!!