Alright, let's work through 91381 times 90642382 step by step
91381 × 90642382 = 90642382 × (91381)
+ 90642382 × 1 that results in 90642382
+ 90642382 × 80 resulting in 7251390560
+ 90642382 × 300 producing 27192714600
+ 90642382 × 1000 resulting in 90642382000
+ 90642382 × 90000 that equals 8157814380000

= 8282991509542
