CCSS.Math.Content.3.MD.C.7
The Standard
Relate area to the operations of multiplication and addition.
Common Core State Standards for Mathematics · Measurement and Data
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students find rectangle area by multiplying side lengths. They split rectangles or rectilinear figures into smaller rectangles, find each partial area, and add the results.
What Mastery Looks Like
- A student can find a rectangle's area from its side lengths and label the answer in square units. The student can split a figure, add partial areas, and explain why the total stays the same.
Common Misconceptions
- Students may confuse area with perimeter or add side lengths instead of multiplying. They may count grid lines instead of squares. When splitting figures, they may overlap sections or leave gaps.
How to Assess It
- Exit ticket: A 5-by-8 rectangle is split into 5-by-3 and 5-by-5 rectangles. Find its area two ways and write both equations.
Lesson moves
Ways to Teach It
Give pairs square tiles to build a 4-by-6 rectangle, split it into two parts, and record multiplication and addition equations.
Ask students to explain in writing why 7 times 5 gives the same area as 7 times 2 plus 7 times 3.
Use matching cards with rectangles, dimensions, multiplication equations, split-area equations, and totals; students race to assemble complete sets.
Show a simple floor plan, then have students split one room into rectangles and calculate the flooring needed in square units.
Free download
Printable 3.MD.C.7 Worksheet
A ready-to-print activity worksheet aligned to CCSS.Math.Content.3.MD.C.7, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetLearning progression
Where This Standard Sits
See the whole path on the Measurement & Data progression map.
Before This Standard
If students are struggling here, check these first.
- CCSS.Math.Content.3.MD.C.6
Counting unit squares gives the area meaning that multiplication arrays and additive decompositions must represent.
- CCSS.Math.Content.3.OA.A.1
Understanding a product as equal groups carries over to seeing tiled rectangles as rows of equal-size units.
- CCSS.Math.Content.3.MD.C.5
Students must understand area as covering with unit squares before connecting rectangular area and decomposed areas to multiplication and addition.
What This Unlocks
Mastery here sets students up for these next.
- CCSS.Math.Content.3.MD.D.8
Area as multiplication supports comparing rectangles with fixed area while perimeter changes, but basic perimeter work can begin without it.
- CCSS.Math.Content.5.MD.C.5
Area arrays, tiling, and decomposition carry over to volume layers, formulas, and adding volumes of non-overlapping solids.
Keep exploring
Related Standards
- CCSS.Math.Content.1.OA.B
Understand and apply properties of operations and the relationship between addition and subtraction.
- CCSS.Math.Content.3.MD.C
Geometric measurement: understand concepts of area and relate area to multiplication and to addition.
- CCSS.Math.Content.2.MD.B
Relate addition and subtraction to length.
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