1. Conversion: 0.001 = 1/1000
2. Multiple: 10 * 0.001 = 10 · 11 · 1000 = 101000 = 1100
Multiply both numerators and denominators. Result fraction keep to lowest possible denominator GCD(10, 1000) = 10
3. Subtract: 1100 - 3 = 1100 - 31 = 1100 - 3 · 1001 · 100 = 1100 - 300100 = 1 - 300100 = -299100
The common denominator you can calculate as the least common multiple of the both denominators - LCM(100, 1) = 100
4. = (-299/100)