 | Swan Sonnenschein (and co, ltd.) - Calculators - 1879 - 20 pages
...the sum of its digits (" Science and Art," Ch. XI. § 8, /). This rule leads to the corollaries : a. A number is divisible by 9, if the sum of its digits is divisible by 9 ; and if not, not. ft. To ascertain the remainder, if any given sum be divided by 9, cast out nines.... | |
 | Adolf Sonnenschein - 1880 - 496 pages
...; .'. the whole is divisible by 9. Note that 27 = the sum of the digits in 153576. Learn by heart : A number is divisible by 9 if the sum of its digits* is divisible by 9. (/) Eeasoning analogous to that just given shews that any number is an exact number of nines + the... | |
 | Education, Higher - 1881 - 504 pages
...trench. If the length dug by each man is 59 yds. 2 ft., find the length of the trench. 9. Prove 'that a number is divisible by 9 if the sum of its digits is divisible by 9. What is the test of divisibility by 11. 10. What is the least quantity which contains each of the following... | |
 | Silas Sadler Packard, Byron Horton - Business mathematics - 1882 - 224 pages
...the three right-hand figures are ciphers, or express a number divisible by 8 ; as 3000 and 7168. 7. By 9, if the sum of its digits is divisible by 9 ; as 216, 783, and 12348. PRIME FACTORS. 16. The Factors of a number are those numbers which multiplied... | |
 | Leonard Marshall - 1883 - 184 pages
...when divided by 9, leaves the same remainder as the sum of its digits when divided by 9. Therefore a number is divisible by 9 if the sum of its digits is divisible by 9. [See § 7 (i.).] (vi.) A number is divisible by 11 if the difference between the sum of its odd digits... | |
 | Education - 1891 - 214 pages
...figure is 0 or 5 is divisible by 5. 6. Any number whose last figure is 0 is divisible by 10. 7. Any number is divisible by 9 if the sum of its digits is divisible by 9. In all the earlier division work encourage promptness, even rapidity, but demand accuracy. Teach the... | |
 | Charles Smith - Algebra - 1888 - 680 pages
...divisible by r-1, it follows that ííj - Nt is divisible by r-1. Ex. 2. Shew that in the ordinary scale a number is divisible by 9 if the sum of its digits be divisible by 9, and by 3 if the sum of its digits is divisible by 3. N - S is a multiple of 9 ;... | |
 | Charles Austin Hobbs - Arithmetic - 1889 - 366 pages
...if its three right-hand figures are zeros, or if the number expressed by them is divisible by 8. (7) A number is divisible by 9 if the sum of its digits is divisible by 9. (8) A number is divisible by 10 if its right-hand figure is 0. (9) A number is divisible by 11 if the... | |
 | David Martin Sensenig - Algebra - 1890 - 204 pages
...each less than 1 — 1 ; hence, e — tí — 0, or с = с-. 871. Cor. — In the decimal system, A number is divisible by 9, if the sum of its digits is divisible by 9. 872. Theorem IV. — If from a number, N, we subtract the digits of the even powers of r, and add those... | |
 | John Fenner Brown - Arithmetic - 1892 - 184 pages
...there are 555 + 88 + 2 of them), and the sum of its digits (in this case, 5 + 8 + 2 + 3 = 18). Hence, A. number is divisible by 9 if the sum of its digits is divisible byd. 5823 is divisible by 9, the sum of its digits being 18, a number divisible by 9. 3746 is not divisible... | |
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A number is divisible by 9 if the sum of its digits is divisible by 9. 
