Alright, let's work through 7160 times 2857 step by step
7160 × 2857 = 2857 × (7160)
+ 2857 × 0 resulting in 0
+ 2857 × 60 what gives us 171420
+ 2857 × 100 resulting in 285700
+ 2857 × 7000 what gives us 19999000

= 20456120
