Alright, let's work through 9643 times 646 step by step
9643 × 646 = 646 × (9643)
+ 646 × 3 that is equal 1938
+ 646 × 40 that results in 25840
+ 646 × 600 that equals 387600
+ 646 × 9000 that is equal 5814000

= 6229378
