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**anky16****Member**- Registered: 2011-02-13
- Posts: 1

how do i find a four digit whole number whose square has last four digits same as the number itself. please suggest a rational solution to it.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,786

Hi anky16;

There is only one solution.

Welcome to the forum!

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi anky16,

Answer and logic is same as bobbym's.

If you want to use equations:

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,395

hi gAr

Neat solution!

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi bob,

Thanks

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

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**alexa.pete9****Member**- Registered: 2011-04-18
- Posts: 11

Decimal numbers such as 3.762 are used in situations which call for more precision than whole numbers provide. As with whole numbers, a digit in a decimal number has a value which depends on the place of the digit. The places to the left of the decimal point are ones, tens, hundreds, and so on, just as with whole numbers.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,786

Hi;

alexa.pete9 wrote:

Decimal numbers such as 3.762 are used in situations which call for more precision than whole numbers provide.

That is not correct. 3.762 is not more precise than the whole number 3. The whole number or integer is exact and implies no error. 3.762 is more precise than the decimal 3.

When you do a calculation with integers such as 7 * 5 = 35, this is exact. (22 / 7 ) ( 67 / 6 ) = 35.095238 is not exact. It implies an error of ± .0000005

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**plutoman****Member**- Registered: 2008-01-06
- Posts: 27

Nice puzzle. Thanks!

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