Alright, let's work through 3915 times 1313 step by step
3915 × 1313 = 1313 × (3915)
+ 1313 × 5 that equals 6565
+ 1313 × 10 what gives us 13130
+ 1313 × 900 that is equal 1181700
+ 1313 × 3000 yielding 3939000

= 5140395
