For example, there are six numbers between 10 and 17.
(1) enumeration: Write the natural numbers from 10 to 17. The natural numbers from 10 to 17 are 10, 1 1 2,666 respectively. The other number is between 10 and 17:1,12, 13, 14, 15,/kloc-. ***6 numbers.
(2) Formula:17-10-1= 7-1= 6. The reason for subtracting 1 is to subtract 17 itself.
Extended data:
Integer addition and subtraction operations:
1, aligned with the same number;
2. Starting from the unit;
3. When the addition reaches dozens, it will be promoted to a higher position; If the subtraction is not enough, subtract 1 from the high position. When this number is added to 10, it will decrease.
The essence of subtraction
1, a number minus several numbers in a line is equal to this number minus the sum of these numbers.
a-b-c-d=a-(b+c+d)
Subtracting the sum of several numbers from a number is equivalent to successively subtracting these numbers from this number.
a-(b+c+d)=a-b-c-d
3. The nature of addition and subtraction mixed operations Remove brackets, and pay attention to the change of addition and subtraction symbols when removing brackets.
a+(b-c)= a+b-c； a-(b+ c)= a-b-c； a-(b-c)=a-b+c