No problem, we've got 1257 and 6447 to multiply
1257 × 6447 = 6447 × (1257)
+ 6447 × 7 that results in 45129
+ 6447 × 50 producing 322350
+ 6447 × 200 resulting in 1289400
+ 6447 × 1000 what gives us 6447000

= 8103879
