Basic Arithmetic — Formal Specification

You can practice arithmetic with negative numbers using randomized quiz questions that apply a 40% independent negation chance per operand. The Skill generates mixed addition, subtraction, and multiplication problems across easy, medium, and hard difficulty levels for classroom or self-assessment drills.

Yes, you can fetch randomized arithmetic quiz questions via the /basicarith-api/question endpoint, which returns JSON objects containing id, a, b, op, prompt, and answer. The /basicarith-api/check endpoint validates integer answers by recomputing results using +, U+2212, and U+00D7 operators.

Yes, the arithmetic quiz supports an on-screen NumPad, global keyboard shortcuts, a timer, and auto-advance on correct answers. It also provides a results table for review, making it suitable for timed classroom drills or self-assessment.

The best way to validate integer answers is using the /basicarith-api/check endpoint, which recomputes results using +, U+2212, and U+00D7 operators and compares Number(answer) for exact integer matches. This ensures deterministic server-backed validation.

The quiz is limited to addition, subtraction, and multiplication operations; it does not support division. Questions are restricted to integer operands and exact integer matches, with no fractional or decimal answer validation available.