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In this lesson, students will learn that a scale drawing shows lengths of an actual object reduced or enlarged according to a ratio called the scale. Students will investigate two different maps, identify their scale, and then use the scale to calculate different actual measures from drawing measures or drawing measures given the actual lengths.
Students then use an interactive tool to experiment with how to convert between scales in different drawings. Students are provided with two worked examples showing two different strategies for converting between scales. They use what they know about ratio and scale to determine the dimensions of enlarged or reduced figures drawn at different scales.
Finally, students review dividing by fractions in the context of determining unit rates. A worked example is provided, suggesting one strategy for determining a unit rate from a fractional rate, and a series of five questions are provided in which students must use fractions and decimals in their answers.
Module 1 Video
The video for this lesson shows how a scale is a ratio of drawing length to actual length, which can be simplified. The video also shows how to construct a scale drawing given the dimensions of an object.