Alright, let's work through 3104 times 6890 step by step
3104 × 6890 = 6890 × (3104)
+ 6890 × 4 yielding 27560
+ 6890 × 00 giving us 0
+ 6890 × 100 that equals 689000
+ 6890 × 3000 producing 20670000

= 21386560
