CCSS.Math.Content.3.MD.C.5a
The standard
A square with side length 1 unit, called "a unit square," is said to have "one square unit" of area, and can be used to measure area.
Common Core State Standards for Mathematics
What this standard means
Students need to understand area as the amount of flat space a shape covers. They should know that a 1 by 1 square is one square unit, and that area is measured by counting how many of those squares cover a shape without gaps or overlaps.
Mastery looks like students explaining why a rectangle covered by 12 unit squares has an area of 12 square units. They often get stuck counting side lengths instead of squares, leaving gaps, overlapping tiles, or saying “units” instead of “square units.”
Ways to teach it
- Have students cover index cards or paper rectangles with 1-inch square tiles, then count the tiles to find the area.
- Ask students to write: How is measuring area with square tiles different from measuring length with a ruler?
- Show three tiled rectangles, one with gaps and one with overlaps, and ask which one shows area correctly and why.
- Connect to floor tiles by asking how many 1-foot square tiles would cover a small classroom rug.
Plan a lesson for CCSS.Math.Content.3.MD.C.5a
Generate a complete lesson plan aligned to this standard, with objectives, activities, and materials. Free, no account needed.
Related standards
- CCSS.Math.Content.3.MD.C.5b
A plane figure which can be covered without gaps or overlaps by n unit squares is said to have an area of n square units.
- CCSS.Math.Content.5.NF.B.4b
Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area i...
- CCSS.Math.Content.5.MD.C.3a
A cube with side length 1 unit, called a "unit cube," is said to have "one cubic unit" of volume, and can be used to measure volume.
- CCSS.Math.Content.3.MD.C.6
Measure areas by counting unit squares (square cm, square m, square in, square ft, and improvised units).