Alright, let's work through 6645 times 4015 step by step
6645 × 4015 = 4015 × (6645)
+ 4015 × 5 resulting in 20075
+ 4015 × 40 producing 160600
+ 4015 × 600 giving us 2409000
+ 4015 × 6000 what gives us 24090000

= 26679675
