No problem, we've got 1388 and 6261 to multiply
1388 × 6261 = 6261 × (1388)
+ 6261 × 8 what gives us 50088
+ 6261 × 80 giving us 500880
+ 6261 × 300 what gives us 1878300
+ 6261 × 1000 resulting in 6261000

= 8690268
