No problem, we've got 1421 and 6398 to multiply
1421 × 6398 = 6398 × (1421)
+ 6398 × 1 resulting in 6398
+ 6398 × 20 that is equal 127960
+ 6398 × 400 what gives us 2559200
+ 6398 × 1000 that results in 6398000

= 9091558
