Alright, let's work through 8407 times 9088 step by step
8407 × 9088 = 9088 × (8407)
+ 9088 × 7 what gives us 63616
+ 9088 × 00 resulting in 0
+ 9088 × 400 yielding 3635200
+ 9088 × 8000 producing 72704000

= 76402816
