# Area

**Strand:** Shape and Space (Measurement)

**Outcome:** 3

## Step 3: Plan for Instruction

### Guiding Questions

- What learning opportunities and experiences should I provide to promote learning of the outcomes and permit students to demonstrate their learning?
- What teaching strategies and resources should I use?
- How will I meet the diverse learning needs of my students?

### A. Assessing Prior Knowledge and Skills

Before introducing new material, consider ways to assess and build on the students' knowledge and skills related to measurement.

Ways to Assess and Build on Prior Knowledge

### B. Choosing Instructional Strategies

Consider the following general strategies for teaching (Van de Walle 2001):

- access prior knowledge on using perimeter in the real world
- introduce area by drawing on familiar and accessible contexts to illustrate uses of area (NCTM 2000)
- review the process used in developing understanding of perimeter and use a similar process in developing understanding of area stressing that the attribute changes but the process is similar:
- explain that the attribute to be measured is area
- check for conservation of area; e.g., rearrange a given shape and determine if the student realizes that the area of the shape remains unchanged
- always estimate prior to comparing or measuring areas
- make direct comparisons; e.g., compare the areas of two shapes by superimposing one shape on the other—subdividing one shape may be necessary
- estimate the area of the shape using nonstandard units of measure; e.g., tiles or lima beans. Use various techniques for estimating area:
- referents—use a referent for the single unit of measure and iterate this unit mentally to obtain the estimate; e.g., use the size of the fingernail on your smallest finger as a referent for 1 cm
^{2}
- chunking—estimate the area of a smaller portion of a shape initially and use this estimate to estimate the entire area of the shape; e.g., estimate the area of a smaller section of the floor and then multiply that answer by the number of these sections in the entire floor

- have the students share their strategies for estimating area
- accept a range of estimates—within 10% or 20% of the actual measure is reasonable (Van de Walle 2001, p. 295)
- encourage the students to measure the area after each estimate so that they develop a better sense of area
- use nonstandard units of measure that have the same attribute as the item being measured; e.g., use tiles or lima beans to measure a given shape
- make indirect comparisons using a nonstandard unit of measure that has the same attribute as the item being measured; e.g., use tiles to measure a desk top and compare this measure to the number of tiles needed to measure another desk top
- measure the area of the shape using larger then smaller nonstandard units of measure to establish that the smaller the unit of measure the more you need to measure the area of a given shape; e.g., more small tiles are needed than large tiles to measure the area of a given shape
- explain the need to use standard units to measure area to facilitate communicating various areas globally
- measure the area of a given shape using an appropriate instrument with standard units of measure; e.g., use transparencies with centimetre grid paper to lay over given shapes to find the areas in square centimeters

- make a simple measuring instrument using familiar unit models; e.g., cut large squares, maybe 30 cm on a side, to measure larger areas and cut small squares, maybe 5 cm to 10 cm on a side, to measure smaller areas. Explain the inverse relationship between the size of the unit used to measure the area of a region and number of units required.

- integrate the strands by:
- using patterns to develop understanding of area
- connecting area to arrays used in relating multiplication and division of whole numbers
- connecting the area concepts to fractions of a region (the denominator of a fraction indicates the number of equal parts into which the region is divided; these equal parts have the same area but not necessarily the same shape).

### C. Choosing Learning Activities

Learning Activities are examples of activities that could be used to develop student understanding of the concepts identified in Step 1.