Let's calculate 1665 x 2399
1665 × 2399 = 2399 × (1665)
+ 2399 × 5 producing 11995
+ 2399 × 60 resulting in 143940
+ 2399 × 600 that results in 1439400
+ 2399 × 1000 that results in 2399000

= 3994335
