We're going to solve 8139 multiplied by 1640
8139 × 1640 = 1640 × (8139)
+ 1640 × 9 yielding 14760
+ 1640 × 30 that is equal 49200
+ 1640 × 100 what gives us 164000
+ 1640 × 8000 that equals 13120000

= 13347960
