Systematic Treatise on Arithmetic: Volume 2

Returning to the Origin: Using the Seven-Division Method; details provided below.

Start of the Value					End of the Value
Ten-thousand	Thousand	Hundred	Ten	Shi (Stone)	Dou
Seven times two is fourteen	Seven times three is twenty-one	Seven times four is twenty-eight	Seven times five is thirty-five	Seven times seven is forty-nine	Call out: seven times nine is sixty-three
Change two to one; add four to the lower place	Change three to two; add one to the lower place	Change four to two; add eight to the lower place	Change five to three; add five to the lower place	Change seven to four; add nine to the lower place	Change nine to six; add three to the lower place
Original Value: Ten-thousand	Thousand	Hundred	Ten	Shi (Stone)	Dou
Call out: the ten-thousand place moves back to combine; count forward to the shi place to get the ten-thousands				Above the method: for every shi, seven mace returns one shi. One place below this is the mace.	The mace returns and moves forward in reverse; ascending to combine, you get the dou.

Seven into one: add three below original: 七一加三. This is an abacus mnemonic for division by 7. When the dividend is 1, the quotient is 0.1 with a remainder of 3 to be added to the next rod.

When reaching seven, advance one to the tens place original: 逢七進一十. If the number on the rod is 7 or more, you divide by 7 and carry 1 to the rod to the left.

Seven into two: add six below 2 / 7 = 0.2 remainder 6.

When reaching seven, advance one to the tens place

Seven into three: forty-two original: 七三四十二. 3 / 7 = 0.4 remainder 2.

Seven into four: fifty-five 4 / 7 = 0.5 remainder 5.

Seven into five: seventy-one 5 / 7 = 0.7 remainder 1.

When reaching seven, advance one to the tens place

Seven into six: eighty-four 6 / 7 = 0.8 remainder 4.

When reaching seven, advance one to the tens place