Alright, let's work through 3503 times 7980 step by step
3503 × 7980 = 7980 × (3503)
+ 7980 × 3 that results in 23940
+ 7980 × 00 what gives us 0
+ 7980 × 500 yielding 3990000
+ 7980 × 3000 yielding 23940000

= 27953940
