No problem, we've got 6915 and 1989 to multiply
6915 × 1989 = 1989 × (6915)
+ 1989 × 5 that equals 9945
+ 1989 × 10 what gives us 19890
+ 1989 × 900 which equals 1790100
+ 1989 × 6000 which equals 11934000

= 13753935
