1. Cross Product**
2. Unit Rate (Mrs. Schaal's favorite)
3. Constant Rate (Needs a ratio table)
4. Constant Rate of Change (Needs a ratio table)
5. Constant of Proportionality (direct variation): K= y
X
6. Graph it on a coordinate plane (Not as reliable, difficult to make accurate)
7. Tape Diagram
8. Double Number LIne
9. Equivalent Ratios
10.. y-y (Doesn't work well if you don't have all 4 numbers)
x-x