Mental Maths Drill

Conventions: 1 n.mile taken as 2,000 yards, 1 knot as 100 yards per three minutes, the radian rule as 33 yards per degree per mile (35.25 exact, BR45 Vol 1 para 0221; 33 for bridge work, BR45 Vol 6 para 0416). Answers are marked to those conventions with tolerance, so a properly done mental answer scores even where the exact figure differs. Category toggles and best scores save in your browser.