LR Abacus Test Portal

A free online Abacus Practice Test created by Lashmi Bai Ravindrapandian as a learning resource for children practicing abacus.

I originally created this practice portal for my son, who is learning abacus and wanted a simple way to practice regularly and improve his speed and accuracy. What started as a small project for him became a free resource that I wanted to share with other abacus learners and parents.

🌐 Practice Online: Abacus Practice Test

👩‍💻 Created by: Lashmi Bai Ravindrapandian 🏫 LR Virtual Classroom: https://lrvirtualclassroom.co.in/ 💻 GitHub: https://github.com/rlashmibai

Why I Created This

Abacus learning takes regular practice, repetition, speed, and accuracy. I wanted to create a simple practice tool that children could use between their classes without needing a subscription or paid account.

This practice portal is completely free to use.

What's inside

• Guest, register, and login flows with session-based auth
• Custom test length (25 / 50 / 100 questions) across addition & subtraction, multiplication, and division
• Practice mode (untimed) and Exam mode (timed, with auto-submit)
• Instant results with a full per-question answer review
• Progress dashboard with charts across a student's test history
• 14 badges/achievements earned automatically from test history
• A printable certificate, unlocked once a student earns their first badge
• Light sound effects and animations across the app
• An About Me page telling the story behind the site

Stack

• Next.js 16 (App Router, Turbopack) + TypeScript + Tailwind CSS 4
• Neon (serverless Postgres) for students, test sessions, and results in production (src/lib/db.ts); falls back to local JSON files under data/ for local development when no database is configured (src/lib/store.ts)
• Hosted on Netlify

Flow

1. Dashboard — a student's stats and a "Start Practice Test" call to action.
2. Test setup — choose operation, digit size, length, and practice vs. exam mode.
3. Instructions — test rules; "Proceed to Test" creates a new test session (POST /api/tests) with a freshly generated question set.
4. Online Test — a live countdown timer (exam mode only) and a question grid. Progress is mirrored to sessionStorage so an accidental refresh doesn't lose answers or reset the clock. The timer auto-submits when it hits zero.
5. Results — score ring, answered/unanswered/correct stats, and a full per-question answer review.
6. Achievements and Certificate — badges earned from a student's result history, and a printable certificate once any badge is earned.

Questions are abacus-style running-sum drills (add/subtract a short sequence of numbers, or multiplication/division problems) generated per level in src/lib/questions.ts.

Getting started

npm install
npm run dev

Open http://localhost:3000. Without a DATABASE_URL set, the portal runs against local JSON files and starts on a seeded demo student defined in data/students.json. Set DATABASE_URL (a Neon/Postgres connection string) to run against a real database instead.