Alright, let's work through 1666 times 6880 step by step
1666 × 6880 = 6880 × (1666)
+ 6880 × 6 what gives us 41280
+ 6880 × 60 giving us 412800
+ 6880 × 600 giving us 4128000
+ 6880 × 1000 that equals 6880000

= 11462080
