Stage 1 - measurement – area
Measure area by placing identical informal units in rows or columns without gaps or overlaps; estimate the size of a given area in square units
- measure area by placing identical informal units in rows or columns without gaps or overlaps
- estimate the size of a given area in square units
Activities to support the strategy
At this Stage, students develop an awareness of what area is and some of the language used to describe area.
Students develop an awareness of the attribute of area through covering activities, colouring in and as comparisons of area are made.
1. Provide students with a collection of shapes or pattern blocks, some which will tessellate and some which will not. Examples include squares, rectangles, triangles and circles. Students choose the best shape to cover a given area, e.g. a piece of cardboard or a book, so there are no gaps or overlaps. Students draw the shape they used. They explain why it was the best shape and describe how the given area was covered.
2. Students use identical square units to make a larger shape of a given area, e.g. students use identical squares to make:
- a square that is 16 square units
- a rectangle that is 20 square units.
Students describe how they arranged the square units to make the larger area and compare their solutions to other students.
Teacher draws all the different solutions on the whiteboard. For example:
Repeat for a different number of square units, but this time students have to think of and list all the possible solutions.
Discuss: If I use the same number but smaller square units, will the total area be the same size?
3. Students estimate how many identical cardboard tiles will cover a given rectangle or square. Check their estimate by covering the shape with tiles. Record the tessellation by tracing or marking.
4. Teacher covers a large rectangle with tiles in rows and columns. Students determine the area of the rectangle in square units. Teacher removes some of the tiles and asks, what is the area of the rectangle now covered by tiles? Remove more tiles. What is the area now?
5. Show students a rectangle that is partly covered with tiles (e.g. one row and one column).
- Ask "How many tiles would completely cover this rectangle? How did you work out your answer? "
- Encourage students to visualise the completed grid, rather than draw the grid lines.
6. Provide students with coloured geometric squares, both plain and patterned. Ask students to select a plain square as the base for their work and some patterned squares.
Students position the squares next to each other so that they create a tessellating shape. The squares are glued into place. Calculate the total area in square units. This activity could follow the theme of making a patchwork quilt.
ACMMG037: Compare and order several shapes and objects based on length, area, volume and capacity using appropriate uniform informal units
MA1-10MG: Measures, records, compares and estimates areas using uniform and informal units.
NSW numeracy continuum
Aspect 7: Unit structure of length, area and volume – Iterates the unit (Uses a single unit repeatedly to measure).