Alright, let's work through 3087 times 6643 step by step
3087 × 6643 = 6643 × (3087)
+ 6643 × 7 that is equal 46501
+ 6643 × 80 resulting in 531440
+ 6643 × 000 that results in 0
+ 6643 × 3000 what gives us 19929000

= 20506941
