Subraction is the next logical extension of addition and yet causes confusion in students both young and old. Why? We were taught to solve subtraction problems in a confusing way.
I am going to show you a very simple way to subtract large (multi-digit) numbers. You will wonder why they never taught this method in school.
First we need to set some reference points so you can follow along with the concept.
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Signing UpStep 1: Subtraction, Why the Confusion?
Subtraction, Why the Confusion
First - Forget what you were taught, subtraction is really a myth. Addition is where it is at.
Next - I am going to assume you already know a little bit about basic arithmatic, because you are already on the Internet and so can read. I will also assume you know what happens when you had 5 pennies and you lost 2 of those pennies.
KISS, Keep It Simple Silly and don't make subtraction hard on youself.
Each example uses only one of each digit, so you will know exactly which digit is referred to.
In text, each digit from an example will be referred to within square brackets [0], other numbers will be without them.
Terms such as minuend (a) - subtrahend (b) = difference (c) are odd words used to identify and denote parts of the subtraction. Now I do not care if you call them 'one' number, without 'the next' number leaves the "answer'. Just that we both know which is which when I mention them.
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North American teaching methods believe the system they taught us is far superior to this European technique. Like-wise with whole word language learning. Don't get me started. LOL
Your example has 6 zeros and the answer has a few too, so it can get real messy real fast describing it, so I'll do each thought process step by step. You will get the aha! moment along the way.
30,000
- 1,500
| | | | |__ think "0 plus 0 gives 0"
| | | |_____ think "0 plus 0 gives 0"
| | |________think "5 plus 5 gives 10" carry forward the 1
| |___________think "1 plus the carried 1 plus 8 gives 10" carry forward the 1
|______________think "the carried 1 plus 2 gives 3"
= 29,500
Working right to left.
It becomes a much more valuable technique the more different the digits are. With so many zero's it is easier to do it other ways, I'll admit.
Now try it with 34,567 - 8,629 and it becomes just as simple as the above.
it quickly becomes
9 + (8) is 17
1 + 2 + (3) is 6
6 + (9) is 15
1 + 8 + (5) is 14
1+(2) is 3
* in the brackets are the answer digits right to left, all the 1's (in this example) are due to carrying forward.
Oh, yeah the answer is 25,938 and with practice can easily be done as quick as you could read it. And it never gets more difficult even when the numbers are larger.
If you do have the aha! moment..... go try subtracting your phone number from your friends, forget about the dashes; and to avoid identical area code thing (yeah use all 10 digits) write one of the numbers in reverse; and you may as well use the higher first digit as the top number.