Alright, let's work through 1639 times 3910 step by step
1639 × 3910 = 3910 × (1639)
+ 3910 × 9 that results in 35190
+ 3910 × 30 that is equal 117300
+ 3910 × 600 that equals 2346000
+ 3910 × 1000 that is equal 3910000

= 6408490
