Alright, let's work through 1399 times 4245 step by step
1399 × 4245 = 4245 × (1399)
+ 4245 × 9 that is equal 38205
+ 4245 × 90 that results in 382050
+ 4245 × 300 that results in 1273500
+ 4245 × 1000 what gives us 4245000

= 5938755
