Showing posts with label math. Show all posts
Showing posts with label math. Show all posts

Thursday, September 30, 2010

Decomposing Cellulose


Arithmetical Analysis, or, Higher Mental Arithmetic for Advanced Classes. 
James B. Thomson. New York, July 1854

Old book, same ol' math. :)

Sunday, August 08, 2010

Roman Numeral Exercises Cheat Sheet

here are the answers for the exercises. if you want to try the exercise first before looking at the cheat sheet, click here. cheers to those who had tried and congratulation who got all correct! g'day.



1.    IX
2.    IX
3.    XII
4.    VI
5.    C
6.    CDXXVII
7.    LXXXI
8.    L
9.    IX
10.   IC
11.   MDCLXVI
12.   CD
13.   XXII
14.   XXX
15.   XXXVIII
16.   MMDCCLI
17.   CXXV
18.   VI
19.   V
20.   No answer. There is no zero in roman numeral. (one of the many shortcomings of roman numeral)



Thursday, August 05, 2010

People! Roman Numeral Exercises! ZOMG!

since i've made a post on roman numeral the other day, it would be fitting to be followed by some exercises on roman numeral. yeah! *excited mode on*. i constructed these questions to test and enhance understanding on roman numeral (yeah, im such a geek, i know). and also as something to challenge our mind while we already up on the internet. people says that the generation who had grown up with the internet readily available are lazy thinkers. well, let's prove that wrong! besides, what's life without challenge ay? :) selamat mencuba!




1.    I  +  II  +  VI  =

2.    XIII  -  IV  =

3.    III  *  IV  =

4.    XC  /  XV  =

5.    VL  +  LV  = 

6.    M  -  DLXXIII  =

7.    IX  *  IX  =

8.    CD  /  VIII  = 

9.    IIIII  =

10.   LXXXII  +  XVII  =

11.   MM  -  CCCXXXIV  =

12.   L  *  VIII  =

13.   LXVI  /  III  =

14.   IIV  -  II  =

15.   XIX  *  II  =

16.   MMDCCLI  /  I  =

17.   VIX / III  =

18.   III  logV  XXV  =

19.   logII  IV  +  logII  VIII  = 

20.   VII  ln  I  = 


you may post your answers on the comments below if you like. ahhh, i have exams for my pe classes tomorrow. iwakidayo @_@. wish me luck! g'dday. :)

Wednesday, August 04, 2010

Let's Learn Roman Numeral!

though i am a math enthusiasts, there aren't that many math related post, oddly enough. well, here's one effort to fix that:


The Romans were active in trade and commerce, and from the time of learning to write they needed a way to indicate numbers. The system they developed lasted many centuries, and still sees some specialized use today.

Roman numerals traditionally indicate the order of rulers or ships who share the same name (i.e. Queen Elizabeth II). They are also sometimes still used in the publishing industry for copyright dates, and on cornerstones and gravestones when the owner of a building or the family of the deceased wishes to create an impression of classical dignity. The Roman numbering system also lives on in our languages, which still use Latin word roots to express numerical ideas. A few examples: unilateral, duo, quadricep, septuagenarian, decade, milliliter.

The big differences between Roman and Arabic numerals (the ones we use today) are that Romans didn't have a symbol for zero, and that numeral placement within a number can sometimes indicate subtraction rather than addition.
Here are the basics:


IThe easiest way to note down a number is to make that many marks - little I's. Thus I means 1, II means 2, III means 3. However, four strokes seemed like too many....
VSo the Romans moved on to the symbol for 5 - V. Placing I in front of the V — or placing any smaller number in front of any larger number — indicates subtraction. So IV means 4. After V comes a series of additions - VI means 6, VII means 7, VIII means 8.
XX means 10. But wait — what about 9? Same deal. IX means to subtract I from X, leaving 9. Numbers in the teens, twenties and thirties follow the same form as the first set, only with X's indicating the number of tens. So XXXI is 31, and XXIV is 24.
LL means 50. Based on what you've learned, I bet you can figure out what 40 is. If you guessed XL, you're right = 10 subtracted from 50. And thus 60, 70, and 80 are LX, LXX and LXXX.
CC stands for centum, the Latin word for 100. A centurion led 100 men. We still use this in words like "century" and "cent." The subtraction rule means 90 is written as XC. Like the X's and L's, the C's are tacked on to the beginning of numbers to indicate how many hundreds there are: CCCLXIX is 369.
DD stands for 500. As you can probably guess by this time, CD means 400. So CDXLVIII is 448. (See why we switched systems?)
MM is 1,000. You see a lot of Ms because Roman numerals are used a lot to indicate dates. For instance, this page was written in the year of Nova Roma's founding, 1998 CE (Common Era; Christians use AD for Anno Domini, "year of our Lord"). That year is written as MCMXCVIII. But wait! Nova Roma counts years from the founding of Rome, ab urbe condita. By that reckoning Nova Roma was founded in 2751 a.u.c. or MMDCCLI.




V
 
Larger numbers were indicated by putting a horizontal line over them, which meant to multiply the number by 1,000. Hence the V at left has a line over the top, which means 5,000. This usage is no longer current, because the largest numbers usually expressed in the Roman system are dates, as discussed above.





Taken from: Nova Roma