Evaluate each expression. When the answer is not a whole number, write your answer as a fraction.

1. \(\text-4 \boldcdot \text-6\)
2. \(\text-24 \boldcdot \frac {\text{-}7}{6}\)
3. \(4 \div \text-6\)
4. \(\frac43 \div \text-24\)

1. How much higher is 500 than 400 m?
2. How much higher is 500 than -400 m?
3. What is the change in elevation from 8,500 m to 3,400 m?
4. What is the change in elevation between 8,500 m and -300 m?
5. How much higher is -200 m than 450 m?

1. A cookie recipe uses 3 cups of flour to make 15 cookies. If you had 4 cups of flour, how many cookies could you make with this recipe? (Assume you have enough of the other ingredients.)
   
2. A teacher uses 36 centimeters of tape to hang up 9 student projects. At that rate, how much tape would the teacher need to hang up 10 student projects?