Alright, let's work through 1315 times 3957 step by step
1315 × 3957 = 3957 × (1315)
+ 3957 × 5 giving us 19785
+ 3957 × 10 what gives us 39570
+ 3957 × 300 resulting in 1187100
+ 3957 × 1000 giving us 3957000

= 5203455
