1, one minus one equals zero.

2. Two minus one equals one.

3. Three minus one equals two.

Four minus one equals three.

Five minus one equals four.

6. Six minus one equals five.

7. Seven minus one equals six.

Eight minus one equals seven.

9. Nine minus one equals eight.

The essence of subtraction

Anti-commutative law: in subtraction, the anti-commutative law shows that subtracting a number is equal to adding the reciprocal of this number. For example, a-b =-b+a.

Law of Association: In subtraction, the law of association shows that if two numbers are subtracted from a number continuously, the sum of the two numbers can be subtracted, or the first subtraction can be subtracted first, and then the second subtraction can be subtracted. Such as a-b-c=a-(b+c).

Equivalent substitution: in subtraction, equivalent substitution means that the result of subtracting a number equal to it is 0. For example, a-a=0.

Difference invariance: in subtraction, difference invariance means subtracting a number (except 0) from a number, and the difference obtained is equal to the original number. For example, a-b=a-c(b and C are not equal).

Subtraction plays a wide role in mathematics and daily life. It can be used to calculate the difference between two numbers, or it can be used to remove a part from the total and find another part. For example, in our daily life, we often need to calculate changes or time intervals, such as the difference between the start time and the end time of an activity, or the time difference between two time points.