NUMB3R2Text Box: Home

Some recent number discussions with friends had us exploring our own number ‘tricks’ and we thought we would share them here. 

 

 

 

 

 

Any number times 1 is itself.  That means you have one of it.  So,

 

1x97,867,564,534,231=

(drum roll please)

97,867,564,534,231
1's

 

 

 

 

Any number times two is double the original number.  They are ALWAYS even, even though the number you multiply by may be odd.  Crazy isn’t it? 

2's

 

 

 

 

Ever hear “3 is a magic number?” 

Well, this is why.  If you have a number, say 345 you add the digits to each other:

           3+4+5= 12

 

If the answer is able to be divided by 3, the original number 345, can too!  How cool is that?  3 divided by 345= 115
Amazing 3'sText Box: Four is the only number which has the same number of letters as is its value. 4 Facts Text Box: Of course, you can always just count on your fingers by 5’s for the 5’s table, but this is also a cool trick I found on Multiplication.com: For even numbers, you take half of the number and put a zero after it: 8x5— take half of 8 (4) and add a zero to it—40! For the odd numbers, subtract one, then follow above steps and end it with a 5. 9x5—subtract 1 from 9 (8) divide in half and end with a 5. 45 5 is the only prime number that ends in 5. Any number with a pattern like this: abc5abc5 is divisible by 5, 73, 137, and 10001! Try it and see!! 5zzzzz

 

 

 

 

The coolest thing about 6’s is, they follow the same rule as threes, with  a twist.   The number is only divisible by six if it is an even number. 

 

  3+4+5=12, so since 3 goes into that and it is even, so does 6

 

But:

    4+4+7=15, since it is odd it can be divided by 3, but not by 6.
Coolness with 6's

 

 

 

 

Toadhaven found some great sights for showing the 9’s tricks. 

Fingering out the 9's

Pick any whole number... If the number is even, divide it by 2; if it is odd, multiply it by 3, then add 1. By repeating this procedure, sooner or later you'll arrive at the number 4, which will give you 2, which in turn gives you 1, and then get a 4 again! No matter what number you choose, you'll always arrive at the 4-2-1 cycle.