Author: Administrator

Measurement — Perimeter and Area

Target Strategies
-Investigate perimeter and area
-Make connections between area and perimeter
-Use familiar units and develop formulas to calculate the area and perimeter of shapes
Preparation
All students to have a 1cm grid board laminated or within a plastic sleeve
Students to have a texta or highlighter for recording, and something to wipe their boards with
Closed Questions
Explain to the students the purpose of your mental routine, e.g. that you are using 1cm grid paper to explore perimeter and area and develop formulas.
I drew a square with sides 4cm long, what was the total perimeter?
The paddock measured 10 metres by 8 metres, what was the total perimeter?
The sides of the rectangle were 5cm and 3cm, what was the perimeter and area?
The area of a square was 9 metres squared, what was the perimeter?
Open Questions
I drew an equilateral triangle, what might the perimeter have been?
I drew a rectangle with a perimeter of 32cm’s, what might it have looked like?
The farmer had an L-shaped paddock, with a perimeter less than 80metres, what might it have looked like?
The area of a shape was 24cm, what might the perimeter be?
Flip Questions
Play Guess the Hidden Perimeter/Area. Draw a shape on your mental routine board. Students need to ask yes or no questions to find out what the hidden perimeter/area is. Questions could include:
Did you use metres as your metric unit?
Is your perimeter greater than 50cm?
Are all your sides equal?
Have you used a parallelogram for your shape?
Keep playing until the perimeter/area is revealed. Encourage no repeat or baby questions for older students. E.g. square, rectangle, more or less than
Extension— Ask students to come up with a mental routine of their own and practise with a peer. Use isometric paper instead of grids for irregular shapes.

Karly Hefferan, 2013