No problem, we've got 1139 and 3945 to multiply
1139 × 3945 = 3945 × (1139)
+ 3945 × 9 which equals 35505
+ 3945 × 30 yielding 118350
+ 3945 × 100 that is equal 394500
+ 3945 × 1000 which equals 3945000

= 4493355
