## 2021 Oregon Math Guidance: 3.GM.C.5

**Cluster: 3.GM.C - Geometric measurement: understand concepts of area and relate area to multiplication and to addition. **

## STANDARD: 3.GM.C.5

### Standards Statement (2021):

Recognize area as an attribute of plane figures and understand concepts of area measurement presented in authentic contexts by tiling and counting unit squares.

### Connections:

Preceding Pathway Content (2021) | Subsequent Pathway Content (2021) | Cross Domain Connections (2021) | Common Core (CCSS) (2010) |

1.GM.A.2, 2.GM.A.3, 2.GM.B.5, 3.GM.A.2 | 3.GM.C.6, 3.GM.D.8 | N/A | 3.MD.C.5 3.GM.C Crosswalk |

### Standards Guidance:

#### Clarifications

- Concept of area is measured with unit squares tiling a plane without gaps or overlaps.
- 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.
- 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.

#### Teaching Strategies

- Students should use numerical and spatial reasoning to determine the area of rectangles in contextual, mathematical problems by counting or tiling.
- Instruction could include grade appropriate use of different measurement systems for area (e.g. in
^{2}/ft^{2}and cm^{2}/m^{2}, etc).

#### Progressions

- Students need to learn to conceptualize area as the amount of two dimensional space in a bounded region and to measure it by choosing a unit of area, often a square. A two-dimensional geometric figure that is covered by a certain number of squares without gaps or overlaps can be said to have an area of that number of square units. (Please reference page 17 in the Progression document).

#### Examples

- A laptop cover is being made with square vinyl stickers. There are four rows of stickers. There are 9 stickers in each row. How many square stickers were used to create the laptop cover?