Pascal's rule

[Death]

Blaise Pascal invent a rule how to check if number divides on another number.

I don't know exactly how it sounds but from school I remember that if sum of digits in given number divides on three, then this number is divides on three.

Also there exist a rules of division on 7, 11 etc.

Can this help us somehow?

I mean make sum of 10000000 and divide it on 3 takes few seconds, not few days, right?

[wblipp]

(edited because what was intended as succinctness read like approbation)

SoB is always looking for ways to speed up the search. Some large improvements in sieving speed happened in part because of discussions on these boards. However, the existing speed improvements have already taken us beyond where this particular idea would be helpful. There are two major reasons why we have already outrun this idea:

Firstly, sieving is about checking whether the numbers are divisible by "small" primes, and that process is already far past the stage where anybody has simple rules.

Secondly, modular arithmetic gives us a way to determine the remainder after division that is much faster than creating the whole number. When the remainder is zero, the number is a divisor.

So no, these rules have additional insight for SoB.

[Death]

thanks for explanation

but division on three is a part oа whole rule

http://ru.wikipedia.org/wiki/%D0%9F%...B0%D0%BB%D1%8F

that's russian version, and alas no english variant
but you can look at math at least

I'll try to find it later.

[jasong]

thanks for explanation

but division on three is a part oа whole rule

http://ru.wikipedia.org/wiki/%D0%9F%...B0%D0%BB%D1%8F

that's russian version, and alas no english variant
but you can look at math at least

I'll try to find it later.

Off-topic:I feel like I'm reading a book in a mirror when I look at Russian. Is there a written or spoken language that both languages are a descendant of? some of the letters seem similar.

[Death]

you can bet that "A" looks and pronounces equal at both languages )))

[Death]

I can't find english version
It should sounds like Pascal's Token or Pascal's Rule
but due to this damn programming language there's a lot of pages that have no common with Blaise Pascal ((