April 17, 2005
Math Activity 2- Just How Far ?
Jason will be traveling across the seas using nautical measurements. How can we land lubbers understand how far he is traveling? By using "conversion" tables to help us out. For example...
A nautical mile is based on the circumference of the planet Earth. If you were to cut the Earth in half at the equator, you could pick up one of the halves and look at the equator as a circle. You could divide that circle into 360 degrees. You could then divide a degree into 60 minutes. A minute of arc on the planet Earth is 1 nautical mile. This unit of measurement is used by all nations for air and sea travel.
A knot is a unit of measure for speed. If you are traveling at a speed of 1 nautical mile per hour, you are said to be traveling at a speed of 1 knot.
A kilometer is also defined using the planet Earth as a standard of distance. If you were to take the Earth and cut it in half along a line passing from the North Pole through Paris, and then measure the distance of the curve running from the North Pole to the equator on that circle, and then divide that distance by 10,000, you would have the traditional unit for the kilometer as defined in 1791 by the French Academy of Sciences.
A nautical mile is 1,852 meters, or 1.852 kilometers. In the English measurement system, a nautical mile is 1.1508 miles, or 6,076 feet. How does this compare to the standard (statute) measure of a mile in feet?
To travel around the Earth at the equator, you would have to travel (360 * 60) 21,600 nautical miles, 24,857 miles or 40,003 kilometers.
Use the lesson activities below to fill in the conversion table. First you will practice using a conversion table to convert units you know, then you will use the information above to create a conversion table of your own.
Here are some interesting links:
Lesson Activities:
Materials:
calculator
unlined paper
pencils/colored pencils
pedometer/odometer
Procedure:
Use the attached table listing the length for nautical miles, statute miles, and kilometers in meters and feet based on the information given in "Just How Far?" Download Worksheet ( To save it to your computer right click and choose Save target as and choose where you want to save it. Open it using Microsoft Word.)
Complete the chart of the following conversions:
inches to centimeters multiply by 2.54 (example: 2 in. X 2.54= approx. 5 centimeters)
centimeters to inches multiply by 0.39 (example: 5 centimeters X 0.30=approx. 2 in.)
feet to meters multiply by 0.30 (example: 9 feet X 0.30= 2.7 meters)
meters to feet multiply by 3.28 (example: 2.7 meters X 3.28= 8.9 feet)
Then complete the second chart on the worksheet by changing nautical miles to miles and kilometers using the information given in the Just How Far section of this lesson.
When you have completed the worksheet, share what you have learned with your class, and attach a copy of it to an email to Barb.
Additional Activities:
Using a car odometer (or a pedometer to measure walking distances), measure the distance from your home to a selected destination, i.e. school. Record the distance in your journal.
Using a calculator and the chart of conversions you made in the preparation section, convert the number of feet/meters you traveled to meters/feet.
Demonstrate the difference between the distances on a line, example: show the number of feet on a line. On a second line, compare the difference between the lengths of metric and standard measure.
Informational Links:
Posted by april at 4:35 AM | Comments (1)
April 2, 2005
Math Activity 1 - Leapin' Lizards
Crocodiles are survivors from the dinosaur age. A crocodile then looked very much like it does now. Crocodiles belong to a reptile family that did not become extinct like most dinosaurs 65 million years ago.
The features of the crocodile today are very similar to what they were 15 million years ago. A crocodile's armor-plated skin is made up of tough scales called scutes. These are reinforced from bony plates just below the surface.
Prehistoric crocodiles were giants, some up to 40 feet (13 meters) long! They preyed on other reptiles, including small dinosaurs. Other prehistoric crocodiles were as small as lizards.
Crocodiles have been honored throughout history. Egyptians in the town of Crocodilopolis had a crocodile god. The ancient Egyptian god of water, Sobek, was in the shape of a crocodile. Alligators, from the same reptilian family as crocodiles, got their name from 'el lagarto,' the Spanish word for lizard!
The estuarine (saltwater) crocodile from Australia, Indonesia, and Southeast Asia is the biggest of all crocs! This massive croc is the only one to swim in the sea. They live in estuaries along the coast and can grow BIGGGGG! The largest saltwater crocodile on record was 27 feet (9 meters) in length and weighed two tons!
With the coming of the European colonists, crocodile habitats became crowded with humans. Both enjoyed the living conditions along the Australian coastal areas. Unfortunately, they couldn't cohabitate as both were creating a problem for the other! No only did crocodiles hunt their prey from the rivers as animals came to drink, they also have the ability to leap as much as 9 feet (3 meters) out of the water after a meal! Crocs began feeding on livestock and then humans nearly hunted the crocs out of existence.
In 1972, crocodile hunting was banned in Australia. It is believed that around 270,000 saltwater crocodile skins and between 200,000 and 300,000 freshwater crocodile skins were exported from Australia before the ban. To meet consumer needs for their meat and their skins, crocodile farms now raise crocs. Poaching of these reptiles has become less of a problem. The croc farms have also become a major tourist attraction, especially at feeding time!
Vocabulary
export
poacher
cohabitate
estuary
prey
ban
Materials
graph paper
colored pencils
clip art to supplement text and graphs
resource material about crocodile and alligator habits and habitats
Procedure:
Based on information collected about similarities and differences between crocodiles and alligators, create a graph, chart or table to display the information. Discuss physical characteristics, i.e. length, shape, eating habits, etc.
Use pictures, drawings, or photographs to enhance your graphs or charts and to highlight features.
Determine suitable intervals for your graph, i.e. crocodile lengths compared to alligator lengths. Use either metric or standard measurements to represent the information.
Use these links to help you research:
Crocodiles.com>
Aborginal Crocs
Marine Bio
Species List
Alligators & Crocs
Posted by april at 4:52 PM | Comments (3)