Alright, let's work through 6659 times 2978 step by step
6659 × 2978 = 2978 × (6659)
+ 2978 × 9 that is equal 26802
+ 2978 × 50 giving us 148900
+ 2978 × 600 which equals 1786800
+ 2978 × 6000 what gives us 17868000

= 19830502
