 | John Fenner Brown - 1892 - 184 σελίδες
...9. 9 is divisible by 3. Any number of 9's are divisible by 3. So, from the previous demonstration, A number is divisible by 3 if the sum of its digits is divisible by 3. 28146 is divisible by 3, for the sum of its digits is 21, a number divisible by 3. 1342 is not divisible... | |
 | Seymour Eaton - 1892 - 252 σελίδες
...multiple of two or more numbers is the least number that is exactly divisible by each of them. Any number is divisible by 3 if the sum of its digits is divisible by S. Any number is divisible by 4 if it end with two or more ciphers, or if the number expressed by its... | |
 | Webster Wells - 1893 - 360 σελίδες
...hence, V. Any number is divisible by 10 if its last digit is 0. Thus, 3790 is divisible by 10. VI. Any number is divisible by 3 if the sum of its digits is divisible by 3. Thus, 582 is divisible by 3, because the sum of its digits, 15, is divisible by 3. VII. Any number... | |
 | Eugene L. Dubbs - 1893 - 244 σελίδες
...the Iy. CM of 8, 12, and 16. Any number is divisible by 2 if it ends with o, or 2, 4, 6, or 8. Any number is divisible by 3 if the sum of its digits is divisible by 3. Thus, 357 is divisible by 3, because 3+5+7, or 15, is divisible by 3. Any number is divisible by 4... | |
 | 1893 - 252 σελίδες
...etc., respectively. Any number is divisible by 4 when the two right-hand digits are divisible by 4. Any number is divisible by 3 if the sum of its digits is divisible by 3. 131. To aid the pupil in determining the prime factors of a composite number the following table is... | |
 | 1898 - 670 σελίδες
...to be added. 2. 2.5X.25X.025X.25=.00390625. 3. Numbers ending in 2, 4, 6, 8, 0 are divisible by 2. A number is divisible by 3 if the sum of its digits is divisible by 3. A number is divisible by 4 when the number denoted by its two right hand digits is divisible by 4.... | |
 | 1898 - 956 σελίδες
...to be added. 2. 2.5X.25X.025X-25=.00390625. 3. Numbers ending in 2, 4, 6, 8, 0 are divisible by 2. A number is divisible by 3 if the sum of its digits is divisible by 3. A number is divisible by 4 when the number denoted by its two right hand digits is divisible by 4.... | |
 | Edwin Pliny Seaver, George Augustus Walton - 1895 - 412 σελίδες
...above, the first part is divisible by 3. The other part is equal to the sum of its digits. Hence a number is divisible by 3 if the sum of its digits is divisible by 3. 4. Divisibility of numbers by 11. ILLUSTRATION. 80000 = 7272 x 11 + 8 6000= 546 x 11 -6 86427 = -j... | |
 | Horatio Nelson Robinson - 1895 - 526 σελίδες
...follows also that every number is an exact number of 9's plus the sum of its digits (§ 77). XI. A number is divisible by 3 if the sum of its digits is divisible by 3. For every number is an exact number of 9's plus the sum of its digits (X and § 77). The part which... | |
 | Edwin Pliny Seaver - 1895 - 408 σελίδες
...determined by the following tests: 1. A number is divisible by 2 if the units are divisible by 2. 2. A number is divisible by 3 if the sum of its digits * is uivisible by 3. Thus, 285 is divisible by 3, for 2 + 8 + 5 = 15 is divisible by 3. 3. A number is divisible... | |
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A number is divisible by 3 if the sum of its digits is divisible by 3• A number is divisible by 9 if the sum of its digits is divisible by 9. 
