Alright, let's work through 8403 times 2513 step by step
8403 × 2513 = 2513 × (8403)
+ 2513 × 3 that equals 7539
+ 2513 × 00 yielding 0
+ 2513 × 400 resulting in 1005200
+ 2513 × 8000 which equals 20104000

= 21116739
