Alright, let's work through 1007 times 31 step by step
1007 × 31 = 31 × (1007)
+ 31 × 7 what gives us 217
+ 31 × 00 that is equal 0
+ 31 × 000 that is equal 0
+ 31 × 1000 what gives us 31000

= 31217
