Alright, let's work through 1399 times 8632 step by step
1399 × 8632 = 8632 × (1399)
+ 8632 × 9 yielding 77688
+ 8632 × 90 yielding 776880
+ 8632 × 300 that equals 2589600
+ 8632 × 1000 producing 8632000

= 12076168
