Alright, let's work through 1231 times 5870 step by step
1231 × 5870 = 5870 × (1231)
+ 5870 × 1 giving us 5870
+ 5870 × 30 what gives us 176100
+ 5870 × 200 that results in 1174000
+ 5870 × 1000 yielding 5870000

= 7225970
