Stage 3 - measurement – squares and rectangles
Students should be able to describe the relationship between length, width and area and use this relationship to calculate areas of rectangles and squares.
Students can:
- establish the relationship between the lengths, widths and areas of rectangles (including squares)
- calculate areas of rectangles (including squares) in square centimetres and square metres
- solve problems involving the areas of rectangles (including squares) in everyday situations, eg determine the area of a basketball court
Activities to support the strategy
Activity 1: calculating areas
Find the area of a variety of rectangles and squares
Record findings in a table.
| Length in cm | Width in cm | Area in cm2 |
|---|---|---|
| 4 | 3 | 12 |
| 3 | 3 | 9 |
| 6 | 2 | 12 |
Activity 2: rectangles
- Use tiles that are 1 cm2 in area to make three different rectangles that have an area of 24 cm2.
- Draw them on grid paper and label both lengths and widths. Students calculate the results, including areas and describe the number patterns which appear.
- Repeat the activity with other areas and record the findings.
Activity 3: making plans
Calculate the areas of floors, play areas, basketball courts, etc. If necessary break areas into rectangular or square parts, to enable easy measurement using trundle wheels, metre rulers or tape measures.
Playground letters: Students work in small groups to design an alphabetic letter on 1 cm grid paper. The letter should have a maximum area of 12 cm2 . Students trace the letter on the playground using a square metre template and convert the square centimetres to square metres. Students find and record the area of their playground letter in square metres.
Hopscotch: Students in pairs make a 50 cm square and discuss how many will be needed to make 1 m2 . Using the 50 cm x 50 cm tile, students design a hopscotch grid that has a maximum total area of 3 m2 . Record the design and the total area.
Handball courts: Students design and draw a diagram of a handball court. Use a metre ruler or measuring tape to draw the handball court in the playground. Estimate the area and check by measuring with paper square metres.
References
Australian curriculum
ACMMG109 Calculate the areas of rectangles using familiar metric units.
NSW syllabus
MA3-10MG Selects and uses the appropriate unit to calculate areas, including areas of squares, rectangles and triangles.