Alright, let's work through 9991 times 5598 step by step
9991 × 5598 = 5598 × (9991)
+ 5598 × 1 that results in 5598
+ 5598 × 90 that is equal 503820
+ 5598 × 900 resulting in 5038200
+ 5598 × 9000 that is equal 50382000

= 55929618
