No problem, we've got 6381 and 4020 to multiply
6381 × 4020 = 4020 × (6381)
+ 4020 × 1 giving us 4020
+ 4020 × 80 that is equal 321600
+ 4020 × 300 that is equal 1206000
+ 4020 × 6000 yielding 24120000

= 25651620
