3rd Grade Math - Additive Property of Area

This post explains and gives practice opportunities related to TEKS 3.6D:

decompose composite figures formed by rectangles into non-overlapping rectangles to determine the area of the original figure using the additive property of area

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Instruction

Area of rectangles is an additive property, which means that the total area of two adjacent, non-overlapping rectangles is the sum of each of their separate areas. Here's a video showing just what that means.

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STAAR Practice

Between 2016 and 2025, this supporting standard has been tested 2 times on the STAAR test. Videos explaining the problems can be found below. If you'd rather take a quiz over these questions, click here. The videos below are linked to the questions in the quiz as answer explanations after the quiz is submitted.

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To view all the posts in this 3rd grade TEKS review series, click here.