Alright, let's work through 7921 times 3891 step by step
7921 × 3891 = 3891 × (7921)
+ 3891 × 1 producing 3891
+ 3891 × 20 what gives us 77820
+ 3891 × 900 giving us 3501900
+ 3891 × 7000 giving us 27237000

= 30820611
