Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2012-12-19 05:04:16

Registered: 2012-12-19
Posts: 1

Hello! This Is RadioBoy

Hello, I have just joined the math is fun forum. I expect interesting things here and will also share my experience of math. For example, the miracle of digit 9. The product of digit nine in interaction with itself will always be nine (9 x 9 = 18 = 1+8 =9).

If you are thinking of switching or using alternative energy in your home, solar power is the best choice that can sustain your lifestyle.


#2 2012-12-19 05:40:06

Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,018

Re: Hello! This Is RadioBoy

Hi RadioBoy

Welcone to the forum! smile

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.


#3 2012-12-19 06:49:47

From: Bumpkinland
Registered: 2009-04-12
Posts: 107,169

Re: Hello! This Is RadioBoy

Hi RadioBoy;

Welcome to the forum.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.


#4 2012-12-19 18:19:52

Registered: 2005-06-28
Posts: 21,812

Re: Hello! This Is RadioBoy

Hi RadioBoy,

Welcome to the forum!

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi. 

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.


#5 2012-12-20 13:13:01

Registered: 2005-01-21
Posts: 7,631

Re: Hello! This Is RadioBoy


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman


#6 2012-12-25 19:38:51

From: Earth
Registered: 2012-11-29
Posts: 3,247

Re: Hello! This Is RadioBoy

Belated welcome to the forum, RadioBoy!

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate


#7 2012-12-25 20:56:07

bob bundy
Registered: 2010-06-20
Posts: 7,743

Re: Hello! This Is RadioBoy

hi RadioBoy,

Welcome to the forum.

For example, the miracle of digit 9. The product of digit nine in interaction with itself will always be nine (9 x 9 = 18 = 1+8 =9).

or a number that reduces to nine eg. 109739369 x 9 = 987654321 ....9+8+7+6+5+4+3+2+1= 45 ... 4+5 = 9.

So here's a challenge:

Why does this happen?

Why doesn't it happen for, say, 7?

What other numbers does it happen for?


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei


Board footer

Powered by FluxBB