Alright, let's work through 7789 times 3940 step by step
7789 × 3940 = 3940 × (7789)
+ 3940 × 9 that results in 35460
+ 3940 × 80 that results in 315200
+ 3940 × 700 producing 2758000
+ 3940 × 7000 resulting in 27580000

= 30688660
