Alright, let's work through 5638 times 1090 step by step
5638 × 1090 = 1090 × (5638)
+ 1090 × 8 producing 8720
+ 1090 × 30 that is equal 32700
+ 1090 × 600 that equals 654000
+ 1090 × 5000 producing 5450000

= 6145420
