Alright, let's work through 3975 times 1660 step by step
3975 × 1660 = 1660 × (3975)
+ 1660 × 5 what gives us 8300
+ 1660 × 70 giving us 116200
+ 1660 × 900 that results in 1494000
+ 1660 × 3000 yielding 4980000

= 6598500
