Alright, let's work through 2400 times 821 step by step
2400 × 821 = 821 × (2400)
+ 821 × 0 that is equal 0
+ 821 × 00 which equals 0
+ 821 × 400 what gives us 328400
+ 821 × 2000 resulting in 1642000

= 1970400
