Calculate the addition and subtraction formula of 75-66+23, and talk about what should be paid attention to when writing addition and subtraction.

32。 Pay attention to addition and subtraction in pen calculation;

1, you can only add and subtract numbers with the same counting unit, that is, the same number of digits should be aligned. Add up to ten and you have to move forward one by one.

2. The pen calculation method of addition and subtraction within 10,000 is: the same digits should be aligned, starting with single digits, which digits add up to ten, and the previous digit should advance by one digit.

3. In the formula without brackets, only addition and subtraction or multiplication and division can be performed, from left to right.