Alright, let's work through 6376 times 620 step by step
6376 × 620 = 620 × (6376)
+ 620 × 6 giving us 3720
+ 620 × 70 what gives us 43400
+ 620 × 300 that is equal 186000
+ 620 × 6000 yielding 3720000

= 3953120
