Table of Contents

• Follow the Units
• 1: The View from the Parking Garage
• 2: How to Follow a Unit
• 3: Following Slowly
• 4: Doing the Two-Step
• 5: A Longer Conversion
• 6: The Second Challenge
• 7: Converting 2 Dimensions
• 8: Converting 3-Dimensional Space
• 9: The View from the Parking Garage

Converting in 2 dimensions

OK, so assuming that we had

how do we convert that into square kilometers (km²)?

Think about the logic of the units. We have meters TWICE on the bottom of the fraction. This corresponds to the LENGTH and WIDTH of the area being searched.

Here's something tempting, but wrong...

How do I know this is wrong? Just follow the units...

Well, we converted meters to kilometers... but only once! Just look at those crazy units! They correspond to a parking garage measured in meters in one direction and kilometers in the other direction.

Moral of the story: if a unit appears TWICE, you will need to convert it TWICE, like so...

Wow, that's a lotta rat.