[tutorials & resource material arranged by topic   MSH! Classes -- Divisibility Tests

Divisible by
1 -- every number
2 -- last digit is even -- 0, 2, 4, 6, or 8.
3 -- sum of the digits is divisible by 3. Repeat as needed.
4 -- last two digits divisible by 4, or if these are both 0, last 3 digits divisible by 4.
5 -- last digit is a 0 or a 5.
6 -- divisible by both 2 and 3, the prime factors of 6.
7 -- (the number created by all but the ones digit) - 2x(ones digit) is divisible by 7. Repeat as needed.
8 -- last 3 digits divisible by 8.
9 -- sum of the digits is divisible by 9. Repeat as needed.
10 -- last digit is 0.
11, 13-- See "A divisibility test for 19" by John Greenacre
12 -- divisible by both 3 and 4.


Other Resourses -- Click Arrow to Open A Window & Make the Jump
 
  "Prime Factorization Puzzle/Practice,"
a prime recognition and prime factorization board. Come play.
 
  Primes Spreadsheet,
with a prime factorization of whole numbers from 1 to 122, whole numbers from from 1 to 500 with primes marked in color, a 50 by 50 times tables
 
  Prime Factorization Text File,
prime factorization of whole numbers from 1 to 122
 
  Sample from Tables of Prime Numbers from 2 to 15,000,000,000
by Charles Dean Pruitt, a large list of ordered prime numbers.
 
  The First 1,000 Primes
from Prime Curios!, by G. L. Honaker, Jr. and Chris Caldwell
 
  A Primality Test
by G. L. Honaker, Jr. and Chris Caldwell, of Prime Curios!
 
 Factorization Using the Elliptic Curve Method
by Dario Alpern, states the prime factorization of a number you type on the page.

 
 
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© June 29, 2003
www.mathnstuff.com/math/spoken/here/2class/30/divisib.htm