Alright, let's work through 3586 times 3910 step by step
3586 × 3910 = 3910 × (3586)
+ 3910 × 6 yielding 23460
+ 3910 × 80 which equals 312800
+ 3910 × 500 that is equal 1955000
+ 3910 × 3000 that equals 11730000

= 14021260
