Alright, let's work through 6749 times 640 step by step
6749 × 640 = 640 × (6749)
+ 640 × 9 yielding 5760
+ 640 × 40 that results in 25600
+ 640 × 700 giving us 448000
+ 640 × 6000 resulting in 3840000

= 4319360
