107.6667
646
646 ÷ 17 = 38 38 + 56 = 94
no, 646 is not evenly divisible by 6
27.5
17
17
6 + 4 + 6 = 16 1 + 6 = 7 → No; 646 is not divisible by 9 (there is a remainder of 7). ----------------------------------------- Only if the sum of the digits is divisible by 9 is the original number divisible by 9. Repeat the test on the sum until a single digit remains; only if this single digit is 9 is the original number divisible by 9, otherwise this single digit is the remainder when the original number is divided by 9.
D is 500, C is 100, XL is 40 and VI is 6. 646 is DCXLVI.
It is: (VI)DCXXXXVI which means 1,000*6+646 = 6,646
646
234 + 646 = 880