Alright, let's work through 2670 times 639 step by step
2670 × 639 = 639 × (2670)
+ 639 × 0 producing 0
+ 639 × 70 which equals 44730
+ 639 × 600 yielding 383400
+ 639 × 2000 that results in 1278000

= 1706130
