No problem, we've got 1656 and 3939 to multiply
1656 × 3939 = 3939 × (1656)
+ 3939 × 6 that results in 23634
+ 3939 × 50 that results in 196950
+ 3939 × 600 what gives us 2363400
+ 3939 × 1000 which equals 3939000

= 6522984
