Alright, let's work through 3502 times 3521 step by step
3502 × 3521 = 3521 × (3502)
+ 3521 × 2 yielding 7042
+ 3521 × 00 what gives us 0
+ 3521 × 500 producing 1760500
+ 3521 × 3000 giving us 10563000

= 12330542
