Re:Finally Getting Two's Complement
by rahimnathwani on Sunday June 25, 2023 @08:55AM
(#36467728)
I don't like the term 'carrying' because it refers to a superficial aspect of the method (that you carry the number from one place to another) rather than the essence of the operation.
When you add, 15+6, you add 5+6 to get 11, and then you regroup the 11 ones into 1 ten and 1 one.
When you subtract 21-6, you regroup the 2 tens into 1 ten and 10 ones. With the original 1 one, you now have 11 ones. Then you subtract the 6 from the 11 ones to get 5 as the last digit.
The term 'borrowing' never made sense to me.
Singapore Math uses the term 'regrouping' which makes a lot more sense: https://www.youtube.com/watch?v=mrDIf3YmNFc
When you add, 15+6, you add 5+6 to get 11, and then you regroup the 11 ones into 1 ten and 1 one.
When you subtract 21-6, you regroup the 2 tens into 1 ten and 10 ones. With the original 1 one, you now have 11 ones. Then you subtract the 6 from the 11 ones to get 5 as the last digit.