Let's calculate 1986 x 10000
1986 × 10000 = 10000 × (1986)
+ 10000 × 6 what gives us 60000
+ 10000 × 80 resulting in 800000
+ 10000 × 900 that is equal 9000000
+ 10000 × 1000 resulting in 10000000

= 19860000
