Alright, let's work through 1345 times 420 step by step
1345 × 420 = 420 × (1345)
+ 420 × 5 that results in 2100
+ 420 × 40 that is equal 16800
+ 420 × 300 that is equal 126000
+ 420 × 1000 that results in 420000

= 564900
