Alright, let's work through 1639 times 350 step by step
1639 × 350 = 350 × (1639)
+ 350 × 9 giving us 3150
+ 350 × 30 that equals 10500
+ 350 × 600 which equals 210000
+ 350 × 1000 what gives us 350000

= 573650
