Alright, let's work through 4020 times 3149 step by step
4020 × 3149 = 3149 × (4020)
+ 3149 × 0 that is equal 0
+ 3149 × 20 yielding 62980
+ 3149 × 000 that equals 0
+ 3149 × 4000 which equals 12596000

= 12658980
