[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]


At 09:57 PM 3/15/2001, philidor11@snet.net wrote:
Me, interrupting:
Unless you're counting on your fingers, what difference does it make whether you're counting by 10's or 12's? And you do have practice counting by 12's. How many hours on your clock? (Even if you're using a 24 hour clock that's still 2 12's.) How many months in the year?

Most people are familiar with a base ten system. We use it for money. We use it for normal, every day counting. How often do you depart from the norm and decide to add up things in a base eight system? Base twelve? Eleven hours is still speaking in a base den system. Two-hundred forty minutes is still in a base ten system.

Speaking from experience, fractions is one of the hardest concepts for students to learn. It is much easier to learn the decimal system than to do fractions.

HP Bowden also notes 'relatedness' as a metric advantage; for example, a cubic metre of water is 1,000 kilograms, and other relationships among
measurements (as well as fall per second per second) are also factors of 10. Contrary to my prior observation, he argues that multiplication/division by 10 is easier because you need 'just keep track of the zeros'. I have some practice with keeping track of zeros. Without a calculator, try to tell someone that 'maybe 0.3% of the 2.5 million adults in the State are current pathological gamblers, based on a telephone survey.' Before I worked out a better way to explain the concept, someone responded that 25 million pathological gamblers was a lot. I gave the number as quoted above to a recently hired (non-research) analyst. He asked about treatment programs for the 75,000 pathological gamblers.
Really, working with factors of 10 is not as easy as it might sound.
I do also think that the ability to respond to the significance, the 'feel'
of the amounts in the current system is important to people.

I disagree. Try adding up a bunch of inches and fractions of inches when you are building something. Now try adding up a bunch of different lengths in mm and cm. As long as you put the decimal place in the right spot, it is the same adding most people have done since their first or second year of schooling. Nobody said all of the math was going to be easy. Metric brings a uniform method of comparison. One prefix is ALWAYS ten units above its predecessor. This is a great deal easier to work with than 12 inches to a foot, 3 feet to a yard, 5.5 yards in a rod, 4 rods in a chain, 10 chains in a furlong, 8 furlongs in a mile. That doesn't even include hands, lines, and leagues and that's just linear measurement.

Darryl Jones  <dinoguy@sympatico.ca>

For information on tyrannosaurids and
cool activities and information for kids,
visit my webpage at: