Alright, let's work through 3905 times 2102 step by step
3905 × 2102 = 2102 × (3905)
+ 2102 × 5 which equals 10510
+ 2102 × 00 that equals 0
+ 2102 × 900 giving us 1891800
+ 2102 × 3000 what gives us 6306000

= 8208310
