Place Value and Similar Numbers
Date: 08/15/2003 at 15:40:33 From: Mrs. Fansler's 6B Math Class Subject: Place value How do you read this number: 10.00001? We were confused because when you read 10.100 you would say "Ten and one hundred thousandths." We believe that when you read 10.00001 it would sound the same. We are guessing that the number would sound the same but you would write each one differently. For example: 10.100 would be written: Ten and one hundred thousandths 10.00001 would be written: Ten and one hundred-thousandth. We would like to know if this is correct.
Date: 08/15/2003 at 16:03:20 From: Doctor Peterson Subject: Re: Place value Hi, Class! Thanks for a good question. I would like to change your question a little to make it harder. The trouble with what you asked is that 10.100 is read as "Ten and one hundred thousandths" with an "s" on the end, so the two DO sound different. Instead, let's use 10.200 = Ten and two hundred thousandths 10.00002 = Ten and two hundred-thousandths Here both are plural, but as you noted, the only difference is the presence of a hyphen, which in reading might mean only that you leave a slightly smaller gap between the words. To make the difference stronger, I might tend to say (or even write) 10.200 = Ten and two-hundred thousandths and exaggerate the difference as much as I could. You're right; there is very little difference. Two details rescue us from having an unusable number system: 1. We rarely say 10.200; usually it would be called 10.2 (though there are reasons for including the extra zeroes, when you get to studying significant digits). 2. In reality (as opposed to elementary school) we would read the numbers as 10.200 = Ten point two-zero-zero 10.00002 = Ten point zero-zero-zero-zero-two This is much easier to say as you read it, easier to figure out when you hear it, and easier to copy down. Who cares if a lot of teachers would say it's illegal! If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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