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Joined 4 years ago
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Cake day: July 3rd, 2020

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  • I tried that for a while, but the autofill was a bit temperamental and switching apps felt a bit tedious.

    My phone alse kept killing Syncthing, even after disabling battery optimisations for it. This left me with lots of sync conflicts and I got a bit paranoid about losing passwords. I love the idea of avoiding cloud-based services but it just wasn’t worth the hassle for me.






  • jouletoAsklemmy*Permanently Deleted*
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    4 years ago

    Divisibility tricks :) here are some of the more interesting ones:

    • 3: digit sum is divisible by 3 (can repeatedly calculate the digit sum until you get to a single-digit number)
    • 4: last two digits are divisible by 4
    • 6: number is divisible by 2 and 3
    • 7: pop the last digit off the number, multiply it by 2 and subtract it from what’s left of the number. Then, check if the new number is divisible by 7 (can repeat if the number is still pretty big) (you might end up with a negative number but it doesn’t really matter, just check whether or not it’s divisible by 7)
    • 8: last 3 digits are divisible by 8
    • 9: digit sum is divisible by 9

    7 is probably the most confusing so I’ll add an example. Say you want to check if 161 is divisible by seven.

    1. pop off the last digit, 1, leaving you with 16
    2. multiply it by 2: 1 * 2 = 2
    3. subtract it from what’s left: 16 - 2 = 14
    4. 14 is divisibly by 7, so 161 is also divisible by 7
    5. if you really wanted to keep going you could ( 1 - 4 * 2 = -7 which is also divisible by 7)