Alright, let's work through 3987 times 679 step by step
3987 × 679 = 679 × (3987)
+ 679 × 7 yielding 4753
+ 679 × 80 giving us 54320
+ 679 × 900 that is equal 611100
+ 679 × 3000 what gives us 2037000

= 2707173
