Unit 6, Lesson 5
One Hundred Percent
Accelerated 6
Preparation
Lesson Narrative
In this lesson, students solve more problems about percent increase and decrease, including problems in which:
- They are given the final amount and the percentage, and they must calculate the original amount.
- They are given the original and final amounts, and they must calculate the percentage.
Students use double number line diagrams to visualize the situations and make sense of which values they were given and what they are trying to find. They see that the starting amount always corresponds to 100%, regardless of whether the situation is an increase or a decrease and regardless of which amount is unknown.
As students explain how to represent situations with double number line diagrams, they construct arguments and critique the reasoning of others (MP3).
- Critique (orally and in writing) double number line diagrams that represent situations involving percent increase or decrease.
- Generalize (orally) that the original amount corresponds to 100% and the new amount corresponds to more or less than 100%, depending on whether the situation involves an increase or decrease.
- Interpret a description of a situation to identify the original amount, the new amount, the change, and corresponding percentages. Label these on a double number line diagram.
Let’s solve more problems about percent increase and percent decrease.
Required Preparation
None