No problem, we've got 1607 and 6640 to multiply
1607 × 6640 = 6640 × (1607)
+ 6640 × 7 giving us 46480
+ 6640 × 00 what gives us 0
+ 6640 × 600 yielding 3984000
+ 6640 × 1000 producing 6640000

= 10670480
