Alright, let's work through 1200 times 687 step by step
1200 × 687 = 687 × (1200)
+ 687 × 0 which equals 0
+ 687 × 00 what gives us 0
+ 687 × 200 giving us 137400
+ 687 × 1000 that is equal 687000

= 824400
