Alright, let's work through 6440 times 1629 step by step
6440 × 1629 = 1629 × (6440)
+ 1629 × 0 which equals 0
+ 1629 × 40 yielding 65160
+ 1629 × 400 giving us 651600
+ 1629 × 6000 that is equal 9774000

= 10490760
