1 and the plus sign are written in the middle of Tian Zige, and the sum of the two addends is written in the left position in the middle of the right half of Tian Zige.

2. The integer part of the minuend and the reduction is written in the middle of Tian Zige, and the symbol of subtraction operation is written in the upper part of Tian Zige, which should be written between the integer part of the minuend and the reduction. This number is written in the lower part of Tian Zige.