Alright, let's work through 8423 times 9992 step by step
8423 × 9992 = 9992 × (8423)
+ 9992 × 3 which equals 29976
+ 9992 × 20 what gives us 199840
+ 9992 × 400 that equals 3996800
+ 9992 × 8000 producing 79936000

= 84162616
