Alright, let's work through 6445 times 4364 step by step
6445 × 4364 = 4364 × (6445)
+ 4364 × 5 giving us 21820
+ 4364 × 40 giving us 174560
+ 4364 × 400 that equals 1745600
+ 4364 × 6000 yielding 26184000

= 28125980
