Alright, let's work through 4237 times 3131 step by step
4237 × 3131 = 3131 × (4237)
+ 3131 × 7 what gives us 21917
+ 3131 × 30 what gives us 93930
+ 3131 × 200 yielding 626200
+ 3131 × 4000 that is equal 12524000

= 13266047
