Measurement: Perimeter, Area, and Capacity
Warm-up
Show two shapes made of linking cubes: one a 1x12 rectangle and one a 3x4 rectangle. Both have 12 cubes (same area). Calculate the perimeter of each. (1x12: 26 units; 3x4: 14 units.) Same area, very different perimeter. This surprise launches the distinction beautifully.
Explore
Measurement stations: (1) Perimeter: measure the perimeter of 5 polygons with a ruler. (2) Area: tile 3 shapes with square tiles and record area. (3) Capacity: pour water between containers and estimate/measure. (4) Circumference: wrap string around 3 circular objects; measure and compare to diameter.
Consolidate
Practice
Students measure perimeter and area of 4 shapes, capacity of 3 containers, and mass of 3 objects. Record all measurements with correct units. Exit ticket: draw two different shapes that each have an area of 12 square units. What are their perimeters?
Exit ticket
Students measure perimeter and area of 4 shapes, capacity of 3 containers, and mass of 3 objects. Record all measurements with correct units. Exit ticket: draw two different shapes that each have an area of 12 square units. What are their perimeters?
Perimeter: 2x(8+3) = 2x11 = 22 metres. Area: 8x3 = 24 square metres. Perimeter is in metres (length units). Area is in square metres (area units). Different attributes, different units, same garden.
Convert to same units: 2L = 2000 mL. 2000 > 1750. The 2L jug holds more by 250 mL.