Alright, let's work through 3899 times 1739 step by step
3899 × 1739 = 1739 × (3899)
+ 1739 × 9 producing 15651
+ 1739 × 90 what gives us 156510
+ 1739 × 800 giving us 1391200
+ 1739 × 3000 resulting in 5217000

= 6780361
