• rumba@lemmy.zip
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    7 days ago

    You can also

    Multiply one side, divide the other to get the base number to get the base number to 100.

    6% of 50 == 3% of 100 == 3

    5% of 20 == 1% of 100 == 1

    7% of 50 == 3.5℅ of 100 == 3.5

    14% of 200 == 7% of 100 == 7

    Edit* as pointed out below, this one was incorrect.

    14% of 200 == 28% of 100 == 28

    You don’t have to stop at percentage either.

    25 * 16 = 100 * 4

    If you’re doing addition, you can add and subtract.

    27 + 13 = 20 + 20

    Most of the difficulty is in realizing that one number or the other can be brought up to a nice round number, making the equation simple to do in your head. And obviously, just getting to around number on one side doesn’t always make it easy on the other side.

    I always loved screwing with math problems to make them easier, which is weird, because overall, I don’t really care for math.

    I also do shit like borrowing a couple of numbers to make the equation easy and then pull them back out.

    392 / 4 == (400 - 8) / 4 == (100-2) = 98

    376 / 4 == (400-24)/4 =100-6=94

    Of course it goes up a level when the remainder isn’t evenly divisible. But I still find it’s something I can handle in my head.

    371 / 4 == (400-29)/4= 100-7¼ =100-7.25=92.75

    • Test_Tickles@lemmy.world
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      7 days ago

      Are you just out here doing common core math on here like it’s just some smart trick to make math easier?! You dirty bastard, some conservative is going to see this and think it’s a good idea, then they’ll just innocently do it in front of their conservative friends and all hell will break loose. Homosexual fornication will suddenly run rampant through the group and those few that can resist the call of the devils numbers will have to cull the rest. You know… Actually… I am not completely against that now that I think about it…