Alright, let's work through 5785 times 3878 step by step
5785 × 3878 = 3878 × (5785)
+ 3878 × 5 producing 19390
+ 3878 × 80 producing 310240
+ 3878 × 700 producing 2714600
+ 3878 × 5000 what gives us 19390000

= 22434230
