Confusedguytoo

[tags via tzikeh]

Fossils tucked away in a museum drawer and identified merely as "feline" are actually from a very ancient and enigmatic saber-toothed cat that inhabited North America more than 5 million years ago. Newly identified by a UC Berkeley paleontologist, the nearly complete skull helps clarify how these large-fanged felines evolved over millennia before going extinct about 10,000 years ago.

It’s so painfully individualistic. Of course me doing that thing isn’t going to save anybody or anything.

Im not trying to be a superhero who personally saves the say.

I am one leaf making oxygen in a massive forest of other trees making oxygen. I am doing my best and having faith that millions of others will do their best as well.

Because that can and has made big changes over time. Like. That is just how change happens. Thats cultural shifts. Thats political shifts. Thats how lasting changes happen.

I don’t plant milkweed because I’m personally gonna save monarch butterflies. I plant milkweed because I know thousands of us are gonna plant milkweed and send money to the people fighting horrible pesticides in court.

This is a given.

If the last digit is divisible by 2 (a.k.a. even), then so is the whole number.

If the sum of the digits is divisible by 3, then so is the whole number. The recursivity of this means that if the sum has multiple digits, you can add them up again until you get a single digit and see if it's 3, 6, or 9.

Like the rule for 2, but check if the last two digits are divisible by 4.

If it ends in 5 or 0.

If the rules for both 2 and 3 apply.

No shortcut. Alas.

Like the rules for 2 and 4, but check if the last three digits are divisible by 8. (Yes, this pattern keeps going for 16, 32, etc.)

Like the rule for 3, but the sum of the digits (or the sum of the sum of the digits, etc.) must be 9.

"Subtract twice the last digit from the rest, check if it gives a multiple of 7. Repeat until it's a small enough multiple for you to recognise."

Example:

92911: 9291 - 2 = 9289

-> 9289: 928 - 18 = 910

-> 910: 91 - 0 = 91

-> 91: 9 - 2 = 7