Perimeter and Area Tile Lab
Measuring a tiled classroom floor and the border around a notice board.
Area covers the inside; perimeter walks around the outside.
A class wants to cover a rectangle with tiles and decorate the border. Decide which number is area and which is perimeter.
Perimeter and Area Tile Lab illustration
Measuring a tiled classroom floor and the border around a notice board.
Find the area and perimeter of a 5 by 4 rectangle.
- Area counts all the inside squares: 5 rows of 4 squares make 20 square units.
- Perimeter counts the outside edges: 5 + 4 + 5 + 4 = 18 units.
Struggle support
Rescue lab
Tiles inside, ribbon outside
A class covers a notice board with square cards and then decorates only the outside edge with ribbon.
Draw a rectangle filled with tiles and trace the outside border with a thick line.
Cover the inside with square counters, then walk a finger around the edge.
Tiles cover area; the finger walk measures perimeter.
Shade inside squares in one colour and outline the boundary in another colour.
Inside squares are counted once; outside edges are added around.
Use separate labels so units do not mix.
Area = 5 x 4 = 20 square units; perimeter = 5 + 4 + 5 + 4 = 18 units.
Using square units for perimeter.
Ask whether the learner counted tiles or walked the edge.
Perimeter uses length units because it measures a boundary line.
Using length plus width for area.
Ask how many rows and how many tiles in each row.
Area covers rows of squares, so multiply rows by columns.
Tap every inside tile, then trace the boundary, before choosing area or perimeter.