No problem, we've got 2939 and 6939 to multiply
2939 × 6939 = 6939 × (2939)
+ 6939 × 9 that equals 62451
+ 6939 × 30 yielding 208170
+ 6939 × 900 resulting in 6245100
+ 6939 × 2000 which equals 13878000

= 20393721
