Part A
From the two buildings she rents, the building costing $643, 225 price is greater than the other that costs $635, 895
Part B
Round to the nearest ten thousand:
$635, 895 ~ $640, 000
this is because 5,895 rounds to 6,000, and then this rounds to 10,000
$643, 225 ~ $640, 000
this is because 43, 225 rounds to 40,000 the nearest ten thousand