Alright, let's work through 1158 times 2104 step by step
1158 × 2104 = 2104 × (1158)
+ 2104 × 8 producing 16832
+ 2104 × 50 giving us 105200
+ 2104 × 100 what gives us 210400
+ 2104 × 1000 yielding 2104000

= 2436432
