Alright, let's work through 6415 times 8378 step by step
6415 × 8378 = 8378 × (6415)
+ 8378 × 5 giving us 41890
+ 8378 × 10 which equals 83780
+ 8378 × 400 that results in 3351200
+ 8378 × 6000 producing 50268000

= 53744870
