1. A Fish Tank Problem
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2. Summary
Proportions are used in real life situation all the time to make estimations. Also, proportions are used to make conversion within the same measuring system and between different systems. Proportions are actually one of the mathematical skills more often used, so it is a good idea to practice proportionality!

3. Vocabulary
Rate: is a ratio that compares two quantities with different units. Ex.: the average speed rate used in the freeways in the Us is  60 miles per hour.
Proportion: Two rates that are equivalent. Or two ratios that are equal,

4. Example: Jeff bought a new fish tank and he wants to know how much time would it take to fill it up with water.
What information does Jeff need in order to answer the question? Share with the whole class your ideas.

5. Jeff does not know the speed of the water flow in his house, nor the water pressure. Everything he has available is a small container that can hold up to 0.5 liters, a stop watch, and he knows he bought a 15 gallon-fish tank.
 Is the information provided, enough to answer the question? How can you use the information provided, to help you answer the question? Be prepare to share with your group..

6. Remember what we have learned in class
Remember what we have learned in class. You need to have the same measurements.
Start by converting gallons to liters. So now go ahead and help Jeff to find out how many liters there are in 15 gallons. Share your answer and your method with your group. (Hint: use any internet browser or your cell phone to find how many liters are equal to a gallon.)

8. After solving the proportion Jeff realized 15 gallons are equal to 56
After solving the proportion Jeff realized 15 gallons are equal to liters.
Now that the unit are the same (liters) Jeff will use the small container and his stop watch to set up a rate he will later use to solve the problem.
Jeff filled up the small container with water and kept track of the time it took to fill up the container with a 0.5 liter capacity. It took approximately 8 seconds to fill up the 0.5 liter container. 
Write a rate that can be used to solve the problem.

9. A possible rate will look like: 8 seconds / 0.5 liter
Now that you have this new piece of information can you find out the time it would take to completely fill the liters fish tank with water?
Now set up an appropriate proportion. How do you think the proportion would look like? 
How much time would it take Jeff to fully fill his fish tank with water?

10. Is this the proportion you came up with?
Solve the proportion
How many minutes will it take?

11. Practice:
How many gallons of water would be need to completely fill a swimming pool with  dimensions 10 ft by 15 ft by 6 ft? What information will you need to solve the problem. Browse the internet to look for the information you need.
Using the same rate used in  Jeff's fish tank problem, how much time would it take to fully fill up the swimming pool? (8 seconds / 0.5 liter)

12. Summary
Once again we explored the many different ways proportionality can be used to make estimations. This time we used proportions to approximate time and to indirectly find the dimension on different 3 dimensional big objects.