Alright, let's work through 8421 times 4890 step by step
8421 × 4890 = 4890 × (8421)
+ 4890 × 1 that results in 4890
+ 4890 × 20 giving us 97800
+ 4890 × 400 resulting in 1956000
+ 4890 × 8000 giving us 39120000

= 41178690
