# Lesson 13

Benchmark Percentages

### Lesson Narrative

The goal of this lesson is to help students understand the connection between benchmark percentages and common fractions (MP7). In these materials, we have identified 10%, 25%, 50%, and 75% as primary benchmark percentages and multiples of 10% as secondary benchmark percentages.

It is common to say that \(25\% = \frac14\) or \(10\% = \frac{1}{10}\). In these materials we avoid this usage and say rather that 25% of a quantity is \(\frac14\) of that quantity, or that 10% of a quantity is \(\frac{1}{10}\) of that quantity.

This lesson builds on understanding of equivalent fractions, multiplying fractions, and dividing by unit fractions from grades 4 and 5.

### Learning Goals

Teacher Facing

- Explain (orally and in writing) how to solve problems involving the percentages 10%, 25%, 50%, and 75% by reasoning about the fractions $\frac{1}{10}$, $\frac14$, $\frac12$, and $\frac34$.
- Generalize (orally) processes for calculating 10%, 25%, 50%, and 75% of a quantity.

### Student Facing

Let’s contrast percentages and fractions.

### Learning Targets

### Student Facing

- When I read or hear that something is 10%, 25%, 50%, or 75% of an amount, I know what fraction of that amount they are referring to.

### CCSS Standards

### Print Formatted Materials

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Student Task Statements | docx | |

Cumulative Practice Problem Set | docx | |

Cool Down | Log In | |

Teacher Guide | Log In | |

Teacher Presentation Materials | docx |