Alright, let's work through 8720 times 5679 step by step
8720 × 5679 = 5679 × (8720)
+ 5679 × 0 giving us 0
+ 5679 × 20 producing 113580
+ 5679 × 700 giving us 3975300
+ 5679 × 8000 that equals 45432000

= 49520880
