Alright, let's work through 3935 times 5187 step by step
3935 × 5187 = 5187 × (3935)
+ 5187 × 5 what gives us 25935
+ 5187 × 30 resulting in 155610
+ 5187 × 900 that equals 4668300
+ 5187 × 3000 yielding 15561000

= 20410845
