Alright, let's work through 2501 times 6581 step by step
2501 × 6581 = 6581 × (2501)
+ 6581 × 1 what gives us 6581
+ 6581 × 00 yielding 0
+ 6581 × 500 which equals 3290500
+ 6581 × 2000 that equals 13162000

= 16459081
