i never liked the "borrowing" method. it gives you too much to think about because you are adding, subtracting, then subtracting.

in my method, i make the second step an "addition" instead of a "subtraction" before i start subtracting the two numbers. by the way, this is pretty useless information. because assuming that you are past middle school...

so you have this problem:

253
-65
----------------------

well people would take this and make the 3 to 13 then subtract 13-5 and then make the 5 to 4. but this is too time consuming and too much to think about when you eye ball a long subtraction problem. here is where i introduce my method.

253
-65
_________________
ok so you can safly assume that the 3 is going to be added by 10. once you do that subtract the two numbers. you make 8. now the next step is the only different part. instead of subtracting 5. add ONE to the 6 instead. so what you should be thinking right now is:

253
-75
--------
8

of course this isn't the right problem. but you should be thinking this. next assume again that "5" is going to be 15.
15-7=8 you got the "7" from before because of the previous subtraction had to be borrowed from.


just do the next step, add one to the next place value. you should be thinking:

253
-175
----------------
88

2-1 is 1 so the answer is 188.

but what if there was a 9 there? well that makes everything easier.


123
-94
----------
ok so do the same thing. 13-4 is 9 now the method i use. ad d one to 9. you make 10. now. whatever number you are subtracting on top, will always equal to the top number. so it is 2. the answer is 29. there you have it. a useless concept but something i still use when i don't have a calculator..

That's pretty neat. I'm still having an internal debate as to whether I actually find that easier, but I'll give it a try.

I'm always interested in alternative approaches to math... Nice job, looks like a good method.

lol if you are still debating then at least this method is working out for you. i am able to just right numbers as soon as i see the next placement value.

^^thanks.

I just did the difference between 253 and 265, which is 12

Then take the 12 and subtract it from 200

188


Its always easy to make the numbers nice and even, and then add or subtract the difference/sum at the end.


ex:

782 - 366

800 - 400 (hold -18 and +34) (you can just get the answer from 34 - 18 right here and add that to the answer of 800- 400)

400 (400 + 16 = 416)

400-18

382 + 34

382 + 30 ( hold +4)

412 + 4

416

At least that's how I have always done it

that looks a little too time consuming. but then again, you have mastered it. as long as it works for you..but that is an interesting way to do it.

These all seem so complicated.. Ive done it like this, and to me seems much simpler.

345 - 237

Take each number at a time.

300 - 200 = 100

40 - 30 = 10

5 - 7 = -2

add together..

108

I use that same trick for addition. Makes it so much easier.

253
-65

My method was as follows:
65 was rounded to 70
100-70= 30
30+5=35 (the 5 from the original rounding)
35+53=88
88+100= 188

For me its just about making the numbers easier.

subtraction pisses me off. So I just make it addition.

253
-65

i just say in my head

65+5=70 total= 5
70+30= 100 total= 35
100+100=200 total= 135
200+50=250 total= 185
250+3=253 total= 188



really easy for me