Exploring area and perimeter

Activity 1: Area and Perimeter concepts

Materials:

Rectangular dot sheets, stationery

Objective:

To understand the relationship between area and perimeter of 2D shapes

Process:

1. Recall area and perimeter concepts: ask students to explain the meaning of area and perimeter in their own words
2. Establish differences between area and perimeter:
   • Perimeter is a one dimensional quantity and area is a two dimensional quantity
   • Area is expressed in sq.units and perimeter in units
   • Area defines the space occupied by a shape, perimeter is the length of its boundary
3. Hand over dot sheets to individual students or pairs of students and inform that the distance between any two horizontally or vertically adjacent dots in the dot sheet is 1 cm
4. Ask students to draw and shade a square of area 1 sq. cm and ask them to find out the perimeter of the same
5. Repeat for 4 sq.cm
6. Ask students to observe these shapes and find out what is the area and perimeter of each shape.
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7. Next, draw this shape on the board/project this image and ask students what is the area and perimeter of this shape. If anyone is unclear, explain how the area and the perimeter can be found out
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8. Ask students to calculate the area of the shaded region (8 sq. cm). Then, ask them to draw a different shape with the same area
9. Next, ask them to compare the perimeter of the shape displayed and the one they drew
10. Call out a few students whose shapes have perimeter lesser, greater and same as the one displayed and share it with the class
11. If there are no examples for any of the categories, challenge them to find suitable shapes

Activity 2: Puzzle

Materials:

Print-outs of the puzzle [or] projector to display and rectangular dot sheets

Process:

1. Handover print outs of the 'Share the land' puzzle(NCERT Class 5 Mathematics Textbook) to students individually or in pairs and ask them to solve it.
2. Discuss different solutions/strategies that students come up with

Activity 3: Game

Materials:

• dot sheets/graph sheets,
• crayons of different colours
• dice (2)

Process:

1. Students are paired/ divided into groups and given the listed materials
2. Each player rolls the dice and draws a rectangle of equivalent size. Eg - if they roll 2 and 4, they draw a 2x4 rectangle.
3. The player who covers maximum area first, wins.
4. Ask students to calculate the perimeter of each rectangle they draw and of their final shape as well.
5. Reference: Conquer the area (activity 2 in https://iheartteachingelementary.com/area-and-perimeter-games/)

Discussion after both activities:

• Does perimeter always increase if area increases?
• Does area always increase if perimeter increases? (If they say yes,give the initial grid examples as reference and ask them to check if it is holding true)