Alright, let's work through 3931 times 4064 step by step
3931 × 4064 = 4064 × (3931)
+ 4064 × 1 that equals 4064
+ 4064 × 30 which equals 121920
+ 4064 × 900 resulting in 3657600
+ 4064 × 3000 producing 12192000

= 15975584
