Alright, let's work through 1720 times 7021 step by step
1720 × 7021 = 7021 × (1720)
+ 7021 × 0 what gives us 0
+ 7021 × 20 that equals 140420
+ 7021 × 700 what gives us 4914700
+ 7021 × 1000 that results in 7021000

= 12076120
