Alright, let's work through 4109 times 2005 step by step
4109 × 2005 = 2005 × (4109)
+ 2005 × 9 that results in 18045
+ 2005 × 00 what gives us 0
+ 2005 × 100 giving us 200500
+ 2005 × 4000 that equals 8020000

= 8238545
