No problem, we've got 3989 and 1515 to multiply
3989 × 1515 = 1515 × (3989)
+ 1515 × 9 yielding 13635
+ 1515 × 80 resulting in 121200
+ 1515 × 900 that is equal 1363500
+ 1515 × 3000 giving us 4545000

= 6043335
