Alright, let's work through 3993 times 7985 step by step
3993 × 7985 = 7985 × (3993)
+ 7985 × 3 yielding 23955
+ 7985 × 90 that is equal 718650
+ 7985 × 900 giving us 7186500
+ 7985 × 3000 that equals 23955000

= 31884105
