Alright, let's work through 4729 times 4257 step by step
4729 × 4257 = 4257 × (4729)
+ 4257 × 9 that is equal 38313
+ 4257 × 20 that is equal 85140
+ 4257 × 700 giving us 2979900
+ 4257 × 4000 what gives us 17028000

= 20131353
