Alright, let's work through 3958 times 7811 step by step
3958 × 7811 = 7811 × (3958)
+ 7811 × 8 giving us 62488
+ 7811 × 50 producing 390550
+ 7811 × 900 that is equal 7029900
+ 7811 × 3000 that equals 23433000

= 30915938
