Alright, let's work through 1345 times 8673 step by step
1345 × 8673 = 8673 × (1345)
+ 8673 × 5 resulting in 43365
+ 8673 × 40 that is equal 346920
+ 8673 × 300 resulting in 2601900
+ 8673 × 1000 giving us 8673000

= 11665185
