Learn on PengiReveal Math, Course 1Module 1: Ratios and Rates

1-1 Understand Ratios

In this Grade 6 lesson from Reveal Math, Course 1, students learn how to define and represent ratios as multiplicative comparisons between two quantities, distinguishing between part-to-whole and part-to-part ratios. Using real-world contexts like lemonade recipes and paint mixtures, students practice writing ratios in three forms — word form, colon notation, and fraction notation — while exploring how equivalent ratios scale across multiple batches. This lesson builds the foundational ratio language and reasoning skills central to Module 1: Ratios and Rates.

Section 1

Describing Ratios with "For Every" and "For Each"

Property

A ratio is a comparison between two quantities. The phrases for every and for each are used to define and describe this relationship verbally.

If a ratio compares quantity aa to quantity bb, it can be stated as:

a for every ba \text{ for every } b

or

a for each ba \text{ for each } b

Section 2

Writing Ratios in Three Notations

Property

A ratio compares two numbers or two quantities that are measured with the same unit. The ratio of aa to bb is written aa to bb, ab\frac{a}{b}, or a:ba:b.

Examples

  • The ratio 20 to 36 can be written as 20 to 3620\ \text{to}\ 36, 20:3620:36, and 2036\frac{20}{36}, which simplifies to 59\frac{5}{9}.
  • The ratio 45 to 18 can be written as 45 to 1845\ \text{to}\ 18, 45:1845:18, and 4518\frac{45}{18}, which simplifies to 52\frac{5}{2}.

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Describing Ratios with "For Every" and "For Each"

Property

A ratio is a comparison between two quantities. The phrases for every and for each are used to define and describe this relationship verbally.

If a ratio compares quantity aa to quantity bb, it can be stated as:

a for every ba \text{ for every } b

or

a for each ba \text{ for each } b

Section 2

Writing Ratios in Three Notations

Property

A ratio compares two numbers or two quantities that are measured with the same unit. The ratio of aa to bb is written aa to bb, ab\frac{a}{b}, or a:ba:b.

Examples

  • The ratio 20 to 36 can be written as 20 to 3620\ \text{to}\ 36, 20:3620:36, and 2036\frac{20}{36}, which simplifies to 59\frac{5}{9}.
  • The ratio 45 to 18 can be written as 45 to 1845\ \text{to}\ 18, 45:1845:18, and 4518\frac{45}{18}, which simplifies to 52\frac{5}{2}.