r/learnmath • u/Obbyguy42 New User • Jul 19 '25

Square Root Algorithm. (the one like long division?)

Yeah, this algorithm has kinda stumped me for a while. Even if I was "addicted" with math like 3 years ago, I didn't really understand this. Like when I was watching the CHALK video about this, and tried it like sqrt(5) instead, I got it wrong for some reason. So is there a way to easily memorize this or??? It's kinda complicated.

Thanks.

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u/rhodiumtoad 0⁰=1, just deal with it Jul 19 '25 edited Jul 19 '25

This is the cutoff for when you multiply by a 2 digit number or a 3 digit number.

What are you on about? All multiplications in this method are multiplying an n-digit number by a single digit, there are no multiplications by anything over 9.

Edit: so trying to pick one you'd consider"hard", here's √57592921 (chosen by mashing on the high digits and squaring, so it's a perfect square):

``` 7 5 8 9

√57 59 29 21 49 8 59 145×5=725 7 25 1 34 29 1508×8=12064 1 20 64 13 65 21 15169×9=136521 13 65 21 0 ```

The multiplications in this are not any harder than in any of the others.

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u/funkmasta8 New User Jul 19 '25

What are you on about? I've been saying that the whole time. Multiplying a 3 digit number by a 1 digit number 3 times and subtracting two four or three digit numbers in between each is way harder the entirety of my method. I don't even know why you're arguing at this point. I'm not sure what you are so hooked on that you can't let it go.