- Topics At a Glance
- Variables
- Variables as Unknown Quantities
- Variable Notations
- Constants
- Expressions and Equations
- Rearranging Expressions
- Commutative Properties
- Associative Properties
- Distributive Properties
- Factoring (Distributive Property in Reverse)
- Combining Like Terms
- Eliminating Parentheses
- Simplifying
- Equations, Functions, and Formulas
- Equations
- Functions
- Independent and Dependent Variables
- Formulas
- Applications to Toolbox
- Evaluating Expressions by Substitution
- Evaluating Formulas by Substitution
- Geometric Formulas
- Four-Sided Shapes
- Three-Sided Shapes
- Circles
**Unit Conversion**- Temperatures
- Weights
**Distances and Speeds**- Money
- In the Real World
- I Like Abstract Stuff; Why Should I Care?
- How to Solve a Math Problem

Let *M* be miles, and let *K *be kilometers:

*K* = 1.609*M**M* = 0.6214*K*

Since (this is one of those important formulas you should probably commit to memory), in order to convert a speed from miles per hour (mph) to kilometers per hour (kph), we multiply by 1.609:

To convert a speed from kph to mph, we multiply by 0.6214.

A sign in Canada says "Speed Limit 100 kph (eh)." How fast is this speed in mph?

To convert a speed from kph to mph we multiply the speed by 0.6214. Therefore, 110 kph is 0.6214(110) = 68.354, or approximately 68 mph. That should be just fast enough to power your way through a moose.

Exercise 1

The speed limit on highways in Michigan is 70 mph. How fast is this speed in kph?

Exercise 2

A walking trail is 10 km long. How long is the trail in miles?