Alright, let's work through 7857 times 9904 step by step
7857 × 9904 = 9904 × (7857)
+ 9904 × 7 that is equal 69328
+ 9904 × 50 that equals 495200
+ 9904 × 800 producing 7923200
+ 9904 × 7000 yielding 69328000

= 77815728
