GIANTS OF THE OCEAN

1. Weights and measures

Objective: To appreciate the different sizes of whales.

Level: K-3, 4-7

Background: Of the 78 species of cetaceans (whales, dolphins and porpoises), 23 live in or swim through British Columbia waters. The Blue Whale is the largest, growing to about 30 metres long, but several other species exceed 15 metres.

Many people confuse dolphins and porpoises, but they are two distinct families of marine mammals. Dolphins are larger, ranging in length from 2.4 to 3.7 metres, while porpoises range from 1.4 to 2.5 metres long. Dolphins are usually beaked and have a larger, moveable dorsal fin. Dolphins have sharp, pointed, conical teeth, and porpoises have small, spade-shaped teeth. Killer Whales (Orcas) are the largest members of the dolphin family.

[PICTURE - relative whale sizes]

Level: K-3

Materials: rope (approx. 30 m long), flagging tape.

Procedure:
1) Cut lengths of rope to equal the lengths of different whales.
2) As a class, students hold different lengths of rope, which are marked every metre with flagging tape. Have each student hold a mark.
3) Count the number of students it takes to equal the length of one whale. Count each student as one metre, two metres, etc.

Level: 4-7

Materials: metre stick or measuring tape, bathroom weight scale, calculators.

Procedure:
1) Have students measure each other's height and calculate the average height of students in the class, then determine how many students it takes to equal the maximum length of a species of whale.
2) Have students weigh themselves and calculate the average weight of students in the class, then find out how many of them it takes to equal the maximum weight of the same species of whale.