Alright, let's work through 1645 times 3159 step by step
1645 × 3159 = 3159 × (1645)
+ 3159 × 5 that equals 15795
+ 3159 × 40 that results in 126360
+ 3159 × 600 what gives us 1895400
+ 3159 × 1000 that results in 3159000

= 5196555
