And we all know how often divisibility-by-seven is needed in our daily lives....
But if you DID need to know a shortcut, it would be: take the last digit, double it, and subtract it from the rest of the number example: 301 you take 1, double it (=2), and subtract it from 30. That gives you 28 which is divisible by seven... so 301 is divisible by seven. (no, really)
See? There are nerd lumberjacks. Other seven facts: 1) You can get seven squirrels in a Ford F150's glove box. (of course, you can always get *less* than seven, but why would you want to?) 2) There are that many "deadly" sins. Coincidentally, there are also that many "fun" ones. (3 of which involve chocolate) 3) it's a prime number. (which means it's a really, really good one) 4) 7 inches is how tall the Leatherface action figure stands. (Texas Chainsaw Massacre)
Dang!! And here I was all ready to do some seven-dividing. Quel domage...
ReplyDelete(My old method, where you just divide it by seven and see if there's a remainder, seems to work pretty well, but I keep hoping there's a better way.)
And we all know how often divisibility-by-seven is needed in our daily lives....
ReplyDeleteBut if you DID need to know a shortcut, it would be:
take the last digit, double it, and subtract it from the rest of the number
example: 301 you take 1, double it (=2), and subtract it from 30. That gives you 28 which is divisible by seven... so 301 is divisible by seven. (no, really)
See? There are nerd lumberjacks.
Other seven facts:
1) You can get seven squirrels in a Ford F150's glove box. (of course, you can always get *less* than seven, but why would you want to?)
2) There are that many "deadly" sins. Coincidentally, there are also that many "fun" ones. (3 of which involve chocolate)
3) it's a prime number. (which means it's a really, really good one)
4) 7 inches is how tall the Leatherface action figure stands. (Texas Chainsaw Massacre)