No problem, we've got 5115 and 1328 to multiply
5115 × 1328 = 1328 × (5115)
+ 1328 × 5 which equals 6640
+ 1328 × 10 giving us 13280
+ 1328 × 100 what gives us 132800
+ 1328 × 5000 what gives us 6640000

= 6792720
