Alright, let's work through 1239 times 3902 step by step
1239 × 3902 = 3902 × (1239)
+ 3902 × 9 that is equal 35118
+ 3902 × 30 yielding 117060
+ 3902 × 200 yielding 780400
+ 3902 × 1000 resulting in 3902000

= 4834578
