Perimeter

Objectives

To implement various mathematical strategies in order to find the perimeter of rectangles and shapes made from joined rectangles.

Resources

Abacus 4 Textbook 2 | Scanner or copier | Squared paper | Perimeter video | Perimeter (YouTube)

Today's Lesson

Main Activity

For mental warm ups, ask your student to recite two or three of their times tables, for revision. Ask for random associated division facts from the chosen tables.

Turn to page 76 in Abacus 4 Textbook 2.

As these involve finding the perimeter of shapes with missing measurements, ask your student how they plan to do this, recalling the information from the discussion during the previous lesson. Ask your student to complete the page, writing directly under the visual aids of the diagrams.

Then attempt and discuss the ‘Think’ section of the page with your student. Do they notice that all the numbers are in the 4x table? Did they try a square measuring 1cm x 1cm? Can they derive a rule (a test for divisibility) for numbers in the 4x table?

Is 100 in the 4x table? What would be the length of one side of a square whose perimeter is 100cm?

Citations

[1] www.youtube.com