Alright, let's work through 2081 times 3819 step by step
2081 × 3819 = 3819 × (2081)
+ 3819 × 1 that is equal 3819
+ 3819 × 80 what gives us 305520
+ 3819 × 000 that is equal 0
+ 3819 × 2000 that is equal 7638000

= 7947339
