CCSS.Math.Content.3.G.A.2
The standard
Partition shapes into parts with equal areas. Express the area of each part as a unit fraction of the whole.
Common Core State Standards for Mathematics · Geometry
What this standard means
Students need to split a shape into equal-area parts and name each part as a fraction of the whole. The parts do not have to look the same, but they must cover the same amount of space. Students should connect the number of equal parts to the denominator, such as 3 equal parts means each part is one third.
Mastery looks like drawing or checking equal shares in rectangles, circles, and other simple shapes, then saying what fraction one part represents. Students often count pieces without checking area. They may also think different-looking pieces cannot be equal, or call one piece “one over the shaded number” instead of using the total number of equal parts.
Ways to teach it
- Give students paper rectangles and scissors, then have them fold and cut the same rectangle into 2, 3, 4, and 6 equal-area parts.
- Ask students to explain: Can two parts look different but still have equal area? Draw an example and defend your answer.
- Show three partitioned shapes and ask students to circle the ones with equal areas and label one part with a unit fraction.
- Connect to sharing a pan of brownies by asking students to draw fair cuts for 2, 4, and 8 friends.
Plan a lesson for CCSS.Math.Content.3.G.A.2
Generate a complete lesson plan aligned to this standard, with objectives, activities, and materials. Free, no account needed.
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