Lesson Objective

Students will use the grid method to enlarge or reduce an image while maintaining perfect proportions.

How does a grid help prevent distortion?

If we double the grid size, what happens to the area of the drawing?

Proportion, Ratio, Enlargement (2:1), Reduction (1:2), Distortion.

CT CTE.AR-D.2.1: Demonstrate the use of scales and proportions.

Students are given a simple drawing on a 0.25-inch grid. They must transfer it to a 0.5-inch grid (enlargement) and a 0.125-inch grid (reduction) point-by-point.

Purpose: To build the mathematical foundation of scaling before using mechanical tools.

DOK Level: 2 (Application).

Use "high-contrast" grids for students with visual processing needs; allow students to color-code grid coordinates.

The "Icon Scale" project—successfully scaling a geometric logo at two different ratios.

 

 Pre-printed grid worksheets, calipers.