Alright, let's work through 3972 times 7855 step by step
3972 × 7855 = 7855 × (3972)
+ 7855 × 2 resulting in 15710
+ 7855 × 70 yielding 549850
+ 7855 × 900 that equals 7069500
+ 7855 × 3000 producing 23565000

= 31200060
