Alright, let's work through 2840 times 3946 step by step
2840 × 3946 = 3946 × (2840)
+ 3946 × 0 yielding 0
+ 3946 × 40 giving us 157840
+ 3946 × 800 giving us 3156800
+ 3946 × 2000 that results in 7892000

= 11206640
