When you've finished, consider the following questions:
1) What strategy did you use to arrive at your answer?
2) If you guessed and checked, what strategy or thinking might you have used to reason to an answer?
3) What mistake do you think others most often make when trying to solve this problem? What causes them to make this mistake?
2) If you guessed and checked, what strategy or thinking might you have used to reason to an answer?
3) What mistake do you think others most often make when trying to solve this problem? What causes them to make this mistake?