I. Addition Mnemonic Chart

Non-incremental addition; progressive addition. Straight plus: full five plus; into ten plus: broken five into ten plus.

One: one on one; one down five to four; one to nine into one.

Two: two on two; two down five to three; two to eight to one.

Three: three on three; three down five to two; three to seven to one.

Four: four on four; four down five to one; four to six to one.

Five: five on five; five to five to one.

Six: six on six; six to four; six to one; six on one to five.

Seven: seven on seven; seven to three into one; seven on two to five into one.

Eight: eight on eight; eight to two into one; eight on three to five into one.

Nine: nine on nine; nine to go one into one; nine on four to go five into one.

Two, subtraction mnemonic table

Non-recessionary subtraction, retreating subtraction. Straight subtraction: break five subtraction; abdication subtraction: back ten to make up for the five subtraction.

One: one down one; one up four to go five; one back one to return nine.

Two: two down two; two up three to five; two back one to eight.

Three: three down three; three up two go five; three back one return seven.

Four: four down four; four up one to five; four back one to six.

Five: five down five; five back one to five.

Six: six down six; six back one to four; six back one to five going one.

Seven: seven down seven; seven back one to three; seven back one to five to two.

Eight: eight down eight; eight back one to two; eight back one to five to three.

Nine: nine down nine; nine back one to one; nine back one to five to four.

Traditional structure

China's traditional abacus for the upper two under the five beads, the upper one represents "5", the lower one represents "1", in the use of the abacus for calculations using the "five liter decimal", that is, each file "full of 5" will use a grain of the upper bead that each file full of "10" will be forward to a file "into the 1 When each file is full of "10", it will "advance 1" to the previous file. Accordingly, each file as long as the next four beads on the next will be enough.

China's traditional abacus is on the two under five beads, the reason is: China's ancient calculation of weight using the "16 two system" that is, a catty is equal to 16 two, so half a catty is equal to eight two. On two under five beads, each file can be calculated to "15", so that "full 16" will be forward a file into one, so our traditional on two under five beads abacus is to adapt to the formation of hexadecimal.