"Breaking the Ten Method" is a calculation method used in the abdication subtraction of mathematics in the first grade of primary school within 20 years. By using the method of "breaking ten", the abdication subtraction within 20 can be transformed into the familiar problem of 10 subtraction, thus making simplification difficult.

For example:? 15-8, when calculating 15 minus 8, first of all, considering that the single digit 5 minus 8 is not enough, so 15 is divided into 10 and 5, and 15 minus 8 gets 2.

The breakdown is as follows:

Add operation

1, add two numbers with the same sign, take the same sign as the addend, and add the absolute values.

2. Add two numbers with different signs. If the absolute values are equal, the sum of two numbers with opposite numbers is 0; If the absolute values are not equal, take the sign of the addend with the larger absolute value and subtract the smaller absolute value from the larger absolute value.

3. Add two numbers with opposite numbers to get 0.

4. Adding a number to 0 still gets this number.

You can add two opposite numbers first.

6. Numbers with the same sign can be added first.

7. Numbers with the same denominator can be added first.