Soroban Kingdom — Key facts
Key facts about Soroban Kingdom (features, levels, pricing and how data is handled) on one page. You are welcome to quote it in articles and blogs. If anything is out of date, please email [email protected].
In one sentence
Soroban Kingdom (sorobankingdom.com) is a browser-based soroban (Japanese abacus) practice app for children aged about 5–15, with a paid teacher screen for parents and abacus schools that shows records, homework and how each child goes wrong.
In three sentences
Children practise mitori (addition/subtraction), multiplication, division, mental arithmetic and flash anzan from 20th Kyu to 10th Dan on any phone, tablet or PC (levels 20–16 are free forever with no sign-up; everything above needs a Home or school plan, with a 14-day free trial and no credit card needed). When an answer is wrong, the app works out the bead move that most likely went wrong (5-complements, 10-complements, carrying) and builds the next day's practice from those mistakes. Schools and families can add a teacher screen — homework with automatic grading, records and a daily list of students who need attention — and set the level table to match the exam system the school follows.
Basic facts
| Name | Soroban Kingdom（そろばんキングダム） |
|---|---|
| URL | https://sorobankingdom.com/ (Japanese) · https://sorobankingdom.com/en/ (English guide pages) |
| Type | Web app (runs in the browser; no App Store / Google Play install). Can be added to the home screen. |
| Devices | iPhone, Android, tablets, Windows / Mac / Chromebook — latest Chrome, Safari or Edge |
| Languages | Japanese, English |
| Operator | Soroban Kingdom Operations Office, Japan (representative: Tomoko Sutou; legal notice). Not affiliated with any abacus examination body, association or franchise. |
| Contact | [email protected] |
| Ages | From about 5–6 (can read and write 1–10) to junior high school. Levels 20th Kyu → 1st Kyu → 1st–10th Dan. |
| Physical soroban | Optional. On-screen soroban included; real soroban can be used alongside (type only the answer). |
Feature checklist
| Feature | Soroban Kingdom |
|---|---|
| Mitori (addition / subtraction) practice | Yes — 20th Kyu to 10th Dan; problems generated fresh each time |
| Multiplication / division | Yes — from 9th Kyu (×) and 7th Kyu (÷) |
| Mental arithmetic (anzan) | Yes — separate anzan levels |
| Flash anzan | Yes — speed and digits by level |
| Error diagnosis | Yes — shows the wrong bead movement as a figure; classifies 5-complement / 10-complement / carrying errors; tracks whether each habit is fading |
| Daily auto-generated practice | Yes — yesterday's mistakes → current level → weak-point drill → flash |
| History / records | Yes — per session; on the device without a plan, in the cloud with a plan |
| Weak-point display | Yes — skill tree independent of level (e.g. "6th Kyu but 10-complements ★5") |
| Mock test and certificate | Yes — SK Test with per-subject time limits; printable certificate |
| Worksheets (PDF/print) | Yes — A4 and US Letter, with answers, unlimited |
| Homework distribution | Yes (teacher screen) — "this week: 7th Kyu mitori × 3 sets"; delivered to the child's screen; results return automatically |
| Record management for teachers | Yes (teacher screen) — per student; students needing attention / struggling / ready to advance |
| Parent access | Yes — weekly summary on the device; full teacher screen with Home plan |
| Match the school's exam system | Yes — presets: SK standard, from 10th Kyu, Nissho/Nichishuren-style, Zenshuren-style, Zenshugakuren anzan-style, UCMAS-style |
| Classroom PC mode | Yes — one shared PC, one drawer per child, 4-digit PIN, auto sign-out after 5 minutes |
| Games | Addition-cross puzzles (unique solution, sized by level), duels. No story mode required to learn. |
| Child's personal data | Nickname only. No real name, birthday, email, address or photo. |
| Ads | None |
| Analytics | Cloudflare Web Analytics only (visit counts; no cookies, does not track individuals) |
Levels (SK standard table)
20th–16th Kyu are the app's own beginner steps (answers up to 5 → up to 9 → using the 5-bead → carrying). From 15th Kyu the formats follow published Japanese abacus exam samples. Milestones: 9th Kyu adds multiplication; 7th Kyu adds division; 6th Kyu is 3-digit mitori; 3rd Kyu is 5-digit × 10 terms and 4-digit × 3-digit; 1st Kyu is 6-digit × 10 terms and 5-digit × 4-digit. Full table: levels page; machine-readable: curriculum/sk.json.
SK Test format
| Subject | Questions | Time | Pass mark |
|---|---|---|---|
| Mitori | 10 | 7 min | 70 / 100 |
| Multiplication | 15 | 7 min | 100 / 150 |
| Division | 15 | 7 min | 100 / 150 |
| Anzan | 10 | 3 min | 70 / 100 |
Pricing (US dollars, outside Japan)
Levels 20–16 are free forever — no sign-up. From 15th Kyu up: Home plan $29/month (up to 3 siblings) or a school plan (Studio $149/month and up).
Try it free for 14 days — no credit card needed. It simply stops after 14 days. If you subscribe, billing starts that day.
| Who | Plan | Monthly | Yearly | Includes |
|---|---|---|---|---|
| Anyone | Levels 20–16 | $0 | $0 | Free forever, no sign-up, every subject. Practice from 15th Kyu up needs a plan |
| Family | Trial | $0 (14 days) | — | No credit card needed; simply stops after 14 days |
| Family | Home | $29 | $290 | Every level plus the teacher screen, up to 3 siblings |
| School | Trial | $0 (14 days) | — | No credit card needed, up to 10 students |
| School | Studio | $149 | $1,490 | Up to 40 students; families pay nothing extra |
| School | Academy | $349 | $3,490 | Up to 150 students |
| School | Franchise | on request | 151+ students, multiple schools | |
The first payment is taken on the day you subscribe, then automatically on the same date every month (every year for yearly plans). Cancel any time from the customer page: the plan stops at the next renewal date and you can keep using it until then. No pro-rated refunds. Payment by credit card via Stripe (Stripe is the merchant of record for USD plans; local tax may be added). Founding Partner offer: the first 20 schools outside Japan get Studio for $99/month for 12 months. Japanese-market prices in yen are on the Japanese pages (Home 2,980 yen; for schools from 4,980 yen for up to 10 students to 39,800 yen for up to 150, per month).
Data and privacy
Children are registered by nickname only; no real names, birthdays, emails or photos are collected. Teachers log in with Google or email. Parents log in with Google for the family trial, the Home plan, or to link a device to their child in a school. The ranking shows a nickname, country, class name and scores — never a real name. Data is stored in Google Firebase (Tokyo region). Credit card details are handled by Stripe and never stored by the site. No advertising. Visits are counted with Cloudflare Web Analytics (no cookies, does not track individuals). Details: privacy policy.
What Soroban Kingdom is not
- Not an official examination. The SK Test is a mock test; certificates are issued by the app, not by any association.
- Not a franchise or a curriculum that replaces a school. It is a tool used alongside a school's own method, or at home.
- Not a native App Store / Google Play app (as of 2026/10/11).
- Not a story-driven game. There is a small kingdom theme, but learning does not depend on it.
Frequently asked questions
What age can a child start?
As soon as they can read and write the numbers 1–10. The first level (20th Kyu) is addition with answers up to 5, so children aged 5–6 can begin. The levels continue up to 10th Dan.
What can I use without signing up?
Levels 20–16 are free forever — no sign-up, no time limit, every subject. Practice from 15th Kyu up, plus records, homework and error diagnosis, needs the Home plan ($29/month, up to 3 siblings) or a school plan (Studio $149/month). Families and schools can try it free for 14 days — no credit card needed. It simply stops after 14 days. If you subscribe, billing starts that day.
Is it an App Store / Google Play app?
No. It runs in the browser at sorobankingdom.com — iPhone, Android, tablets and PCs (Chrome / Safari / Edge). "Add to Home Screen" makes it behave like an app. Nothing to install.
Do we need a physical soroban?
No. The on-screen soroban can be used directly. In a classroom, children can also solve on a real soroban and type only the answer. Either way, a wrong answer shows the bead move that most likely went wrong, worked out from the answer.
Is it affiliated with an abacus examination body or franchise?
No. The SK Test is Soroban Kingdom's own mock test. Its formats (digits, number of terms) follow published Japanese abacus exam samples but are the app's own guideline. Schools can set the level table to match the system they follow (Japanese kyu/dan variants, or a UCMAS-style ladder).
Can families use it without a school?
Yes. With the Home plan children practise every level and parents get the teacher screen (records, weak points, homework). If the child later joins a school that uses Soroban Kingdom, they simply join with the school's key.
Which languages?
Japanese and English. Switch in the child's ⚙️ settings, the 🌐 button on the teacher screen, or with ?lang=en. English guide pages are at sorobankingdom.com/en/.
Other pages
For schools · For families · SK Test · Levels · Finger technique · Complements of 5 and 10 · Legal · llms.txt
This page is maintained by the operator and updated when facts change. Last updated 2026/10/11.