1-2=1 easy as that
It means the Same thing as borrowing.
Associative property does not work with subtraction because not all numbers can be subtracted and have the same results............
The 4 basic arithmetic operations are addition, multiplication, division, and subtraction. subtraction is the inverse (opposite) of addition the same way around and the same concept as division and multiplication.
Because a negative negative is the same a a positive, and because of the definition of subtraction and addition.
Subtraction is commutative... in a way. You can convert any subtraction to an addition. 7 - 2 is NOT the same as 2 - 7. However, when turning the terms around, you may keep the sign, so that 7 - 2 is the same as -2 + 7. This is justified by the commutative law of addition. Similarly with division: 10 / 2 is not the same as 2 / 10, but you can convert 10 / 2 into (1/2) x 10.