Alright, let's work through 6420 times 3943 step by step
6420 × 3943 = 3943 × (6420)
+ 3943 × 0 that is equal 0
+ 3943 × 20 that results in 78860
+ 3943 × 400 that is equal 1577200
+ 3943 × 6000 that results in 23658000

= 25314060
