# Area counting with Coco

TLF ID L139

Find the area of rectangles on a grid. Explore how the formula works for finding a rectangle's area. First, estimate the area of a chosen rectangle or compound rectangular shape on a grid. Second, work out the correct formula for finding area by placing rows and columns of squares inside the rectangles. Then, compare the actual area of the original shape with your first estimate. Practise applying the formula directly to a range of rectangular shapes. Includes finding the area of: 1. Rectangles; 2. Polygons made up of rectangles. This learning object is a combination of two objects in a series.

#### Educational details

Key learning objectives
• Students estimate the area of rectangles.
• Students investigate the attribute of area by covering rectangles and compound shapes made up of rectangles.
• Students use arrays to cover a shape in systematic ways.
• Students explore the formula for calculating the area of rectangles.
• Students apply their understanding of the formula to calculate the area of rectangles and compound shapes made up of rectangles.
Educational value
• Encourages students to estimate the area of compound rectangular shapes drawn on a grid.
• Relates the counting of squares in rows and columns to the area of a rectangle rule.
• Provides opportunities for students to practise multiplication facts and addition.
• Provides immediate feedback and helpful hints to students, where necessary.
• Alerts students to the accuracy of their estimation.
Year level

4

TopicsArea; Rectangles
Learning area
• mathematics
Strand
• Mathematics/Measurement and geometry
Concept
• Mathematics/Polygons
• Mathematics/Area
• Mathematics/Arithmetic
• Mathematics/Counting strategies
• Mathematics/Estimation
• Mathematics/Formulas
Skill
• Analysis;
• Application;
• Comprehension;
• Knowledge
Student activity
• Interactives;
• Experiment;
• Analysis;
• Modelling;
• Problem solving;
• Estimation
Learning design
• Experiential learning;
• Independent learning;
• Problem solving;
• Visual learning

#### Other details

Contributors
• Author
• Organisation: University of Western Sydney
• Address: Penrith South NSW 2750 Australia
• URL: http://www.uws.edu.au/
• Technical implementer
• Publisher
• Date of contribution: 20 Sep 2013
• Organisation: Education Services Australia
• Address: Melbourne VIC 3000 Australia
• URL: http://www.esa.edu.au/
Access profile
• Colour independence
• Hearing independence
Learning resource type
• Interactive Resource
Browsers
• Microsoft Internet Explorer - minimum version: 8.0 (MS-Windows) - maximum version: 9.0 (MS-Windows)
• Firefox - minimum version: (MS-Windows)
• Safari - minimum version: 5.1 (MacOS)
Operating systems
• MacOS - minimum version: 10.6
• MS-Windows - minimum version: XP - maximum version: 7
Rights
• © Education Services Australia Ltd, 2013, except where indicated under Acknowledgements.

Includes: