Let's calculate 9991 x 4721
9991 × 4721 = 4721 × (9991)
+ 4721 × 1 that is equal 4721
+ 4721 × 90 that is equal 424890
+ 4721 × 900 resulting in 4248900
+ 4721 × 9000 that equals 42489000

= 47167511
