Alright, let's work through 5258 times 1646 step by step
5258 × 1646 = 1646 × (5258)
+ 1646 × 8 that equals 13168
+ 1646 × 50 what gives us 82300
+ 1646 × 200 giving us 329200
+ 1646 × 5000 that equals 8230000

= 8654668
