Lesson Plan

Distinguish between an additive comparison ("4 more apples than oranges") and a multiplicative comparison ("3 apples for every 1 orange"), and identify the ratio as the multiplicative comparison.

Use ratio language -- "for every ___ there are ___" and "the ratio of ___ to ___ is ___ to ___" -- to describe a ratio relationship between two quantities.

Write a ratio in all three standard notations: a to b, a:b, and a/b, and translate among them.

Recognize that the order of a ratio matters -- a:b and b:a describe different relationships.

Classify a ratio as part-to-part (comparing two parts of a group) or part-to-whole (comparing a part to the total), and determine the whole when the ratio is part-to-whole.

Read a part-to-whole ratio as a fraction of the whole (boys are 2/5 of the class) while recognizing that this fraction-of-the-whole reading does not apply to part-to-part ratios.

Write a complete ratio statement for a real-world situation, including units, order, all three notations, ratio language, and part-to-part / part-to-whole classification.

6.RP.A.1

Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, "The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak." "For every vote candidate A received, candidate C received nearly three votes." -- Standard 6.RP.A.1