Alright, let's work through 4150 times 400 step by step
4150 × 400 = 400 × (4150)
+ 400 × 0 which equals 0
+ 400 × 50 producing 20000
+ 400 × 100 what gives us 40000
+ 400 × 4000 giving us 1600000

= 1660000
