Florida B.E.S.T. MA.3.GR.2.4
The Standard
Solve mathematical and real-world problems involving the perimeter and area of composite figures composed of non-overlapping rectangles with whole-number side lengths.
Florida B.E.S.T. Standards for Mathematics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students break a composite figure into separate rectangles. They use side lengths to find each area, combine the areas, and add only the outside edges for perimeter.
What Mastery Looks Like
- Students split an irregular figure into rectangles and label needed side lengths. They find each rectangle’s area, add the areas, and calculate perimeter using only the outside edges.
Common Misconceptions
- Students may add the perimeters of each rectangle and count shared sides twice. They may confuse area with perimeter, include interior lines in the perimeter, or use square units for both measures.
How to Assess It
- Give this exit ticket: Two rectangles, 6 by 4 units and 3 by 2 units, share one 2-unit side. Find the total area and outside perimeter, and show your work.
Lesson moves
Ways to Teach It
Give pairs grid paper and square tiles to build an L-shape, split it into rectangles, then find its area and perimeter.
Ask, “Why can two L-shapes have the same area but different perimeters?” Students draw examples and explain their reasoning.
Play Match the Figure: students pair composite-figure cards with correct area and perimeter cards, then justify one match.
Plan a patio made from two rectangular sections, then calculate paving area and the length of edging needed.
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Printable MA.3.GR.2.4 Worksheet
A ready-to-print activity worksheet aligned to MA.3.GR.2.4, with an answer key for the teacher on its own page. No account needed.
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Related Standards
- MA.4.GR.2
Solve problems involving the perimeter and area of rectangles.
- MA.3.GR.2.3
Solve mathematical and real-world problems involving the perimeter and area of rectangles with whole-number side lengths using a visual model and a formula.
- MA.3.GR.2
Solve problems involving the perimeter and area of rectangles.
- MA.4.GR.2.1
Solve perimeter and area mathematical and real-world problems, including problems with unknown sides, for rectangles with whole-number side lengths.
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