We're going to solve 2121 multiplied by 5215
2121 × 5215 = 5215 × (2121)
+ 5215 × 1 producing 5215
+ 5215 × 20 producing 104300
+ 5215 × 100 which equals 521500
+ 5215 × 2000 resulting in 10430000

= 11061015
