2. What is a formula?  An equation that shows a relationship between quantities that are represented by variables  Ex: d = rt, p = l x w, etc…

3. How do I use the rate formula?  Suppose you travel 162 miles in 3 hours. Use the formula d = rt to find your average speed.  Plug in numbers for variables  D = distance  R = rate  T = time

4. I need to find the missing number/variable…  D = 273 miles  T = 9.75 hours  Find r  D = 540. 75 in  R = 10.5 in/yr  Find t

5. When do I use substitution?  You can estimate the temperature outside using the chirps of a cricket. Use the formula F = n/4 + 37, where n is the number of times a cricket chirps in one minute, and F is the temperature in degrees. Estimate the temperature when a cricket chirps 100 times a minute.  Formula –  F = n/4 + 37

6. What is perimeter?  Perimeter is the distance around a figure  Can find by adding all sides of a figure  Formula = P = 2L + 2W

7. Find the perimeter… 12.5 18.5

8. Classwork  3-3 Practice in Workbook  Turn in when finished!