Alright, let's work through 10000 times 1290 step by step
10000 × 1290 = 1290 × (10000)
+ 1290 × 0 yielding 0
+ 1290 × 00 resulting in 0
+ 1290 × 000 that is equal 0
+ 1290 × 0000 what gives us 0
+ 1290 × 10000 giving us 12900000

= 12900000
