In Tian Zige, Arabic numerals 1 to 9 are written in the square near the left.

One digit and ten digits of two digits occupy a grid respectively.

Vertical type means that each transition number is changed by the last transition number, and then the single digits of the last transition number are multiplied by 2. If carry is needed, proceed to 1, then increase the unit number by ten digits, and so on, and add a new operand to the unit number.