the.com/divisibility
The art of splitting evenly, which is more than most people manage.
means The property of a number that lets it be divided by another number with nothing left over.
from Built from 'divisible,' which traces back to Latin 'dividere' — 'to divide,' from 'dis-' (apart) plus a root related to 'videre'... actually no, linked more plausibly to a root meaning 'to separate' — the 'vid/vis' piece shares ancestry with words of splitting and sighting apart. The '-ity' suffix, from Latin '-itas,' turns the quality into a noun: not just divisible, but the abstract fact of being so. Mathematicians inherited the word wholesale from everyday Latin-rooted vocabulary, sharpening it into a precise rule about remainders equaling zero.
- rule for 3
- Sum the digits, if divisible by 3 so is the number
- rule for 11
- Alternate add and subtract digits, check against 11
- zero exception
- Every nonzero number divides zero, zero divides nothing
- prime link
- Primes are numbers with exactly two divisors, period