Alright, let's work through 6404 times 3568 step by step
6404 × 3568 = 3568 × (6404)
+ 3568 × 4 that results in 14272
+ 3568 × 00 giving us 0
+ 3568 × 400 giving us 1427200
+ 3568 × 6000 what gives us 21408000

= 22849472
