Alright, let's work through 1646 times 5074 step by step
1646 × 5074 = 5074 × (1646)
+ 5074 × 6 that results in 30444
+ 5074 × 40 producing 202960
+ 5074 × 600 producing 3044400
+ 5074 × 1000 that equals 5074000

= 8351804
