Alright, let's work through 2780 times 778 step by step
2780 × 778 = 778 × (2780)
+ 778 × 0 yielding 0
+ 778 × 80 that equals 62240
+ 778 × 700 yielding 544600
+ 778 × 2000 that is equal 1556000

= 2162840
