Lesson 16

Finding the Percentage

Lesson Narrative

While students have found percentages with easy numbers before now, in this lesson they will develop a general structure (MP7) that will work for any numbers.

Learning Goals

Teacher Facing

  • Critique or justify (orally) statements about percentages and equivalent numerical expressions.
  • Generalize a process for finding the percentage that C is of B and justify (orally) why this can be abstracted as $\frac{C}{B} \boldcdot 100$.

Student Facing

Let’s find percentages in general.

Learning Targets

Student Facing

  • I can solve different problems like “60 is what percentage of 40?” by dividing and multiplying.

CCSS Standards

Addressing

Glossary Entries

  • percent

    The word percent means “for each 100.” The symbol for percent is %.

    For example, a quarter is worth 25 cents, and a dollar is worth 100 cents. We can say that a quarter is worth 25% of a dollar.

    A quarter (coin)
    A diagram of two bars with different lengths.
  • percentage

    A percentage is a rate per 100.

    For example, a fish tank can hold 36 liters. Right now there is 27 liters of water in the tank. The percentage of the tank that is full is 75%.

    a double number line