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conulyI don't remember how it came up, but a few days ago she commented that 51 isn't a prime number, even though it sure feels like it ought to be one.
I feel the exact same way!
And it's really silly, because 51 = 3 x 17 (I memorized it because I got tired of confusing it for a prime number) and it should be obvious with any two digit number whether or not those digits add up to a multiple of 3. (And in a base 10 system, if they do, that means the number is divisible by 3 and, of course, not prime.)
Nevertheless, even after memorizing the factors, I can never quite shake the feeling that 51 ought to be a prime number. And apparently, neither can Mommy.
I feel the exact same way!
And it's really silly, because 51 = 3 x 17 (I memorized it because I got tired of confusing it for a prime number) and it should be obvious with any two digit number whether or not those digits add up to a multiple of 3. (And in a base 10 system, if they do, that means the number is divisible by 3 and, of course, not prime.)
Nevertheless, even after memorizing the factors, I can never quite shake the feeling that 51 ought to be a prime number. And apparently, neither can Mommy.
