The Soroban Site of the Visual Math Institute

Smart Moves

These are the suggestions for soroban fingering from Kojima (1954; p. 29). These are optional, and nobody should be inhibited by them. On the other hand, it is suggested that the earlier one learns them, the better. Tey are the subject of Dril #0 and Tutorial #7.

Fingering, all cases

• 0. Push LOWER beads UP with the thumb. For all other moves use the first finger.

Order of moves on one rod

• 1. Push LOWER beads UP (thumb) and an UPPER bead DOWN (finger) simultaneously. We call this move the pinch.
• 2. Push LOWER beads DOWN (finger) then an UPPER bead UP (finger) in this order. We call this move the check (quick down then up).
• 3. Push an UPPER bead DOWN (finger) then LOWER beads DOWN (finger) in this order. We call this move the flick (quick down and down).
• 4. Push LOWER beads UP (thumb) and an UPPER bead UP (finger) simultaneously. We call this move the double-push.

Order of moves on two adjacent rods

• 5. For ADDITION, move on the RIGHT rod, then the LEFT rod.
• 6. For SUBTRACTION, move on the LEFT rod, then the RIGHT rod.

Smarter Moves

Regarding rule #5 on the order of moves for addition, we are advised by our mentor, Dr. Kouzi Suzuki, that experts break them. He wrote us on 11 January 2011:

There are two ways of thinking of addition:
Example 3+9

Explanation:

(1) Add ten first (SAKIDAMA in Japanese: SAKI means ahead or first, DAMA means bead). We are supposed to add nine but we can not put nine on ones' place because there are already three there. Therefore add ten first then take away one. Because add nine is the same as add ten and take away one.

(2) Take away one first (ATODAMA in Japanese: ATO means after) then add ten, as you know one and nine is ten. Ministry of Education and Science in Japan math textbook gives only way (2). But soroban school teachers are fond to explain way (1), because it is much faster.