1. For addition, write two addends into two columns and insert a plus sign between the two numbers.

2. For subtraction, write two minuets into two columns and insert a minus sign between the two numbers.

3. For multiplication, write two multipliers into two columns and insert a multiplication symbol between the two numbers.

4. For division, write two dividend numbers into two columns and insert a division symbol between the two numbers.

The writing format of off-type calculation is generally to divide the calculation steps into several steps, each step retains two decimal places, and the calculation order is indicated according to the requirements of the topic. In the recursive equation, the numbers that do not participate in the operation should be written down, and their positions in the recursive equation cannot be changed. Recursive equation is a kind of question calculation method which is beneficial to cultivate students' initial logical thinking ability.

When calculating disjoint, multiply and divide first, then add and subtract. If multiplication and division are connected, they should be operated from left to right in turn. If addition and subtraction are connected, they should be operated from left to right in turn. Deformation calculation is widely used in mathematics learning, which is the basis and one of the important contents of mathematics learning.

Operating rules for offline calculation:

1, you must calculate multiplication and division first, and then add and subtract.

2. In the calculation of multiplication and division, it must be calculated from left to right in sequence. When you encounter parentheses, you must first calculate the inside of the parentheses.

3. In the separation process, the operation sequence line should be drawn according to the operation sequence, and the "three checks" should be carried out. First, check whether the numbers and symbols copied from books to exercise books are consistent; The second is to check whether the numbers and symbols copied from horizontal to vertical are correct; Third, check whether the draft is copied correctly in the vertical and horizontal directions, and whether there are any omissions.