49999+4999+1999+499+49+5
= (49999+1)+(4999+1)+(1999+1)+(499+1)+(49+1)
= 50000 + 5000 + 2000 + 500 + 50
= 57550
382-98
= 382 - 100 + 2
= 282 + 2
= 284
(215+357+429+581+625)-(205+347+419+571+615)
= (215-205)+(357-347)+(429-419)+(581-571)+(625-615)
= 10 + 10 + 10 + 10 + 10
= 50