Entry: teach me dis!! Wednesday, September 29, 2004



There are two facts concerning the square of an integer that are useful in the inverse process of finding the square root. The first concerns the number of digits. In short:

If 0 < a < 10 then 0 < a2 < 100,
if 10 < a < 100 then 100 < a2 < 10 000,
if 100 < a < 1000 then 10 000 < a2 < 1 000 000,
.
.
.

The point to see here is that the square of an integer has either twice as many digits as the integer itself, or one less than twice as many. So, since 9,409 has 4 digits its square root has 2 digits, and the square root of the 13 digit number 3,871,696,594,290 has 7 digits.

The second fact concerns the "geometry" of squaring a number. Consider, for example, the square of 249 so the geometric object to consider is a square with side of length 249 units. Write 249 as 200 + 40 + 9 then the square can be seen as







and the square of 249 is 200x200 + 2(200x40) + 40x40 + 2(240x9) + 9x9 = 62001.

Now to find the square root of an integer you need first to determine the number of digits there will be. Let us find the square root of 64 009. Since 64 009 has 5 digits, the square root of 6 | 4 0 | 09 will have 3 digits. First recall some of the geometric detail of a 3 digit number.

A square of a 3 digit number is divided into 7 parts as shown in the diagram






  please! im begging you! if you have time! teach me please! i ahve been trying to understand this for 2 days now! i still cant! my exams are next week! last day namin bukas for review! wla kami pasok sa monday! maawa keio saken!! keilangan ko ng tulong!! seryosong tulong please!! if anyone cud teach me yahoo! messenger: astigishpopshit please! please! please!

   4 comments

sam
October 19, 2004   07:55 PM PDT
 
i've added you na sa YM..:) mine is sam18_smile
calculus
October 6, 2004   02:12 PM PDT
 
Naku!!! sayang at ngayon ko lang ito nabasa. I could have helped you
claire
October 1, 2004   08:06 PM PDT
 
*miles: haha!! pti nga kuya ko di marunong e!!
miles
October 1, 2004   12:05 AM PDT
 
oh God. if only I could remember how to do that!

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