 | Isaac Dalby - Mathematics - 1806 - 526 pages
...x : Euler however, has found the theorem 32 defective when x — 32, for 2 + 1 = 641 x 6700117815. If the sum of the digits of a number is divisible by 9, the number itself is also divisible by 9. Let a, b, c, d, be the digits of a number consisting of... | |
 | Charles Davies, William Guy Peck - Mathematics - 1855 - 628 pages
...formulas, in which / denotes the length of the edge, s the area of the surface, and r the volume : 5. If the sum of the digits of a number is divisible by either 3, or 9, the number itself will also be divisible by the same number, 3 or 9 6. If a number... | |
 | James Stewart Eaton - Arithmetic - 1857 - 376 pages
...Division by casting out the 9's are founded. (g) The properties given for 9 are equally true for 3 ; ie if the sum of the digits of a number is divisible by 3, the number is itself divisible by 3, and if the sum of the digits divided by 3 gives a remainder, then the number... | |
 | Ireland commissioners of nat. educ - 1865 - 184 pages
...the sum of the digits of a number is divisible by 9 the sum itself is divisible by 9 or 3. 7th. When the sum of the digits of a number is divisible by 3 the number itself is divisible by 3. 8th. Whenthesura of thedigitsstandingintheeven places is equal to the sura of the digits standing in... | |
 | Stoddard A. Felter, Samuel Ashbel Farrand - Arithmetic - 1875 - 316 pages
...number ending with 5 or a zero is divisible by 5; as, 305, 240. 8. If the sum of the digits of any number is divisible by 3, the number itself is divisible by 3 ; as, 612, 822. 7. What are the lowest terms of | ? Of -f^ ? Of -^ ? Of A? of A? of A? w. offt? om?... | |
 | William Guy Peck - Arithmetic - 1877 - 430 pages
...3.136. NOTE. — If the final digit of a number is 0, 2, 4, 6, or 8, the num ber is divisible by 2. If the sum of the digits of a number is divisible by 3, the number itself is divisible by 3. If the final digit of a number is 5, the number is divisible by 5. 20. 930. 23. 1,738. 26. 1,105. 21. 1,455.... | |
 | Alexander Kennedy Isbister - 1882 - 190 pages
...the sum of the digits of a number is divisible by 9 the mm itself is divisible by 9 or 8. 7th. When the sum of the digits of a number is divisible by 3 the number itselt is divisible by 3. 8th. When the sun. of the digits etandmgm the even places is equal to the... | |
 | John Bascombe Lock - Arithmetic - 1891 - 400 pages
...the sum of the digits of an even number is divisible by 3, the number itself is divisible by 6. When the sum of the digits of a number is divisible by 3, and its last two digits are divisible by 4, the number itself is divisible by 12. *62. A number is... | |
 | Clarence Monroe Bookman - Arithmetic - 1914 - 268 pages
...number exactly divisible by 2. 43. Tests of divisibility : 1. All even numbers are divisible by 2. 2. If the sum of the digits of a number is divisible by 3 or 9, the number is divisible by 3 or 9. 3. If the two right-hand figures of a number are ciphers or... | |
 | Clarence Monroe Bookman - Arithmetic - 1914 - 270 pages
...number .exactly divisible by 2. 43. Tests of divisibility : 1. All even numbers are divisible by 2. 2. If the sum of the digits of a number is divisible by 8 or 9, the number is divisible by 3 or 9. 3., If the two right-hand figures of a number are ciphers... | |
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Similarly, if the sum of the digits of a number is divisible by 3, the number is divisible by 3. 
