80in8 Mental Math Trainer

A calibrated 80-in-8 challenge with +1 / −1 scoring (pass = 56). Practice uses the same locked mental-arithmetic engine.
TEST · STORED

🎯 80in8 Challenge

Exact format: 80 four-option MCQ in 8:00. Integers, fractions & decimals across +, −, ×, ÷. +1 right, −1 wrong, no skipping. Score 56+ to pass. Every attempt saved with advanced stats.

PRACTICE · NOT STORED

🧮 Practice Drill

3:00 timer. Target integers, decimals, fractions, multiplication and division. Same difficulty engine, no penalty scoring.

📊 80-in-8 history & stats

No 80-in-8 attempts yet. Take the test to start tracking.

🧮 Practice history & stats

No practice sessions yet. Run a drill to start tracking.
All data is stored locally in your browser only — nothing leaves this device.
Charts are rendered offline; no internet connection required.