Alright, let's work through 3947 times 5134 step by step
3947 × 5134 = 5134 × (3947)
+ 5134 × 7 yielding 35938
+ 5134 × 40 that equals 205360
+ 5134 × 900 which equals 4620600
+ 5134 × 3000 resulting in 15402000

= 20263898
