We're going to solve 7851 multiplied by 1806
7851 × 1806 = 1806 × (7851)
+ 1806 × 1 that is equal 1806
+ 1806 × 50 that is equal 90300
+ 1806 × 800 what gives us 1444800
+ 1806 × 7000 that equals 12642000

= 14178906
