No problem, we've got 4021 and 7639 to multiply
4021 × 7639 = 7639 × (4021)
+ 7639 × 1 what gives us 7639
+ 7639 × 20 that is equal 152780
+ 7639 × 000 that equals 0
+ 7639 × 4000 that results in 30556000

= 30716419
