Alright, let's work through 3939 times 8424 step by step
3939 × 8424 = 8424 × (3939)
+ 8424 × 9 what gives us 75816
+ 8424 × 30 producing 252720
+ 8424 × 900 that results in 7581600
+ 8424 × 3000 giving us 25272000

= 33182136
