Alright, let's work through 2578 times 5240 step by step
2578 × 5240 = 5240 × (2578)
+ 5240 × 8 producing 41920
+ 5240 × 70 that equals 366800
+ 5240 × 500 producing 2620000
+ 5240 × 2000 giving us 10480000

= 13508720
