Unit 2 Contents

Before cleaning the aquarium, Jacob drains all the water. The aquarium was full when he started draining it. A little later he sees that it is full. Jacob estimates that about of the tank has drained out so far.

6. Make an estimate of your own. Is Jacob's estimate too high or too low? Explain your reasoning.
7. Find the exact amount of water that has drained out of the fish tank by solving the problem with fraction circle pieces.
8. Write a number sentence for your solution to Question 7.
9. Does your estimate in Question 6 agree with your answer in Question 7? Explain.

After cleaning the aquarium, Jacob refills it with a small hose from the sink. When he first checks the tank, it is full. Two minutes later, it is full.

10. Estimate how much water was added to the tank during the two minutes. Show the location of your estimate by marking an “X” on a number line like the one shown below.

Jacob decides to solve the problem without using circle pieces.

11. Is Jacob's answer reasonable? Why or why not?
12. If his answer is not reasonable, what mistake did Jacob make?
13. Use circle pieces to find an exact answer to the problem. Include a number sentence.