Parents' Column | Soroban
How soroban-style mental math works:
until the beads appear in your head
A child who learns soroban can find the answer without a soroban, moving their fingers slightly. That is “soroban-style mental math” (shuzan-shiki anzan). Why it is so fast, how it is learned, what research has and hasn’t shown, and what you can do at home — from our experience in soroban classrooms.
What soroban-style mental math is
Ordinary mental math works in words and digits in your head: “7 plus 5 is 12.” Soroban-style mental math is different. You picture a soroban (the Japanese abacus) in your head and move the beads on it to get the answer. When a child who learns soroban does mental math while moving their fingers slightly on the desk, it is because they are flicking the beads of the soroban in their head.
Try it: the soroban below moves when you tap the beads. Try setting 7: bring down one upper bead and push up two lower beads, and that’s 7.
Tap a bead to move it. The upper bead is 5; each lower bead is 1.
Set this number on the soroban–
There is also a page with a 5-rod soroban where you can play more. Go to Play with a soroban.
Why is it so fast?
- Numbers have become “shapes”
On a soroban, every number is shown as a bead shape. With practice, just hearing “7” brings up the shape “upper bead plus two lower beads.” Because the number is seen as a picture, there is less hesitation.
- Calculation has become “bead movement”
Addition and subtraction are done with set bead movements (such as “add 5 and take away 4”). Because these movements have been practiced over and over, they can be made in the head in just the same way.
- Place value is seen at a glance
On a soroban, the beads are lined up rod by rod. On the soroban in the head, too, the ones, tens and hundreds are clearly separated, so place-value mistakes are less likely.
Three steps to learning it
| Step | What it looks like |
|---|---|
| ① Move the beads correctly on a real soroban | The stage of learning the finger movements, until moving the beads becomes second nature. This is the foundation of everything |
| ② In the head, while moving the fingers | The stage of calculating with finger movements only, without a soroban in front of them. Some children close their eyes to calculate |
| ③ With only the soroban in the head | The finger movements get smaller and the beads move in the head. It starts with 1-digit numbers, and the digits increase little by little |
Doing mental math while moving the fingers is not a mistake. It is an important stage, while the soroban in the head is still growing. As children get used to it, the finger movements naturally become smaller. As a rough guide, it takes one to two years to learn, but it differs for each child, depending on how long they have attended and how much they practice.
What research has shown
Soroban-style mental math has long been studied by psychologists and brain researchers. Here, honestly, is what is known and what is not.
| Topic | What is known |
|---|---|
| Memory for digits | Experts in soroban-style mental math could remember about 15–16 digits (ordinary adults manage about 7). This strength applied to digits only and was not seen for letters or words (Hatano & Osawa, 1983) |
| The soroban in the head | Children who learned soroban-style mental math calculated faster and more accurately than children who had not. About 3–4 digits can be held in the head at once (Stigler, 1984; Frank & Barner, 2012) |
| How the brain works | When experts did mental math, the regions that handle shapes and space were more active than the language regions (Tanaka et al., 2002; Hanakawa et al., 2003) |
| Effects on children | In a three-year trial following 204 children aged 5–7, calculation skills and understanding of place value improved greatly. In a separate one-year trial, however, no clear difference appeared, because few children had yet acquired the soroban in the head (Barner et al., 2016, 2017) |
In other words, the effects show clearly once a child has truly acquired the soroban in the head. We can’t go as far as saying “soroban makes you smarter,” but research does confirm that calculation skills and understanding of place value grow. For more about how the brain works, see The benefits of soroban.
What you can do at home
- Eyes closed, 1-digit addition: Ask “What’s 3 plus 4?” and have your child answer with their eyes closed. If their fingers move, that’s proof they are flicking the beads in their head.
- Number-card game: Show cards with numbers written on them, one at a time, adding as you go. Keep a good rhythm, and keep the amount small enough to stay fun.
- Calculating while shopping: “If you buy a ¥60 snack with ¥100, how much change do you get?” Everyday calculations make good mental-math practice.
For all of these, short and fun is what matters. If the answer is wrong, don’t give the right answer straight away; try saying, “Picture the beads once more.”
Frequently asked questions
If my child stops soroban, will they lose the mental math too?
Even if the bead movements fade little by little, the image of numbers tends to stay. Many children who continued to 3rd kyu or higher can still do mental math as adults.
Can a child who is weak at mental math still learn it?
Yes. Mental math comes after practicing moving the beads correctly on a real soroban. The shortest route is first becoming solid at addition and subtraction on the soroban.
At what age does mental-math practice start?
Once a child has started soroban and got used to moving the beads, they can begin with simple 1-digit mental math. For when to start, see also When should a child start soroban?.
Does it clash with the mental math taught in school math?
At first, some children are confused by having two methods. Both are correct ways of calculating, so the teacher reassures them that “the school’s way matters too” as they go. With practice, children learn to use whichever suits the situation.
References: Barner, D. et al. (2016) Child Development 87(4) / Barner, D. et al. (2017) Journal of Numerical Cognition 3(3) / Frank, M. C. & Barner, D. (2012) Journal of Experimental Psychology: General 141(1) / Hanakawa, T. et al. (2003) NeuroImage 19(2) / Hatano, G. & Osawa, K. (1983) Cognition 15 / Stigler, J. W. (1984) Cognitive Psychology 16(2) / Tanaka, S. et al. (2002) NeuroReport 13(17)
Close your eyes, and a soroban appears in your head!
About the author
Taito MoritaFounder & principal of Kodomo School (Morita Group Co., Ltd.)
He carries on the Morita Juku founded in Toyohashi in 1972. Through soroban, calligraphy and art at about 90 classrooms in Aichi and Shizuoka and at our Hanoi school in Vietnam, he helps children build the strength to believe in themselves. He also gives talks and seminars on education.
Message from our founderTalks & seminarsUpdated: October 8, 2026
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