Alright, let's work through 7813 times 1987 step by step
7813 × 1987 = 1987 × (7813)
+ 1987 × 3 yielding 5961
+ 1987 × 10 producing 19870
+ 1987 × 800 yielding 1589600
+ 1987 × 7000 producing 13909000

= 15524431
