Alright, let's work through 8399 times 4831 step by step
8399 × 4831 = 4831 × (8399)
+ 4831 × 9 what gives us 43479
+ 4831 × 90 that is equal 434790
+ 4831 × 300 resulting in 1449300
+ 4831 × 8000 what gives us 38648000

= 40575569
