Alright, let's work through 1720 times 6978 step by step
1720 × 6978 = 6978 × (1720)
+ 6978 × 0 giving us 0
+ 6978 × 20 resulting in 139560
+ 6978 × 700 what gives us 4884600
+ 6978 × 1000 producing 6978000

= 12002160
