Alright, let's work through 6405 times 4932 step by step
6405 × 4932 = 4932 × (6405)
+ 4932 × 5 what gives us 24660
+ 4932 × 00 that is equal 0
+ 4932 × 400 producing 1972800
+ 4932 × 6000 that equals 29592000

= 31589460
