Whats 1+1 its just too hard plz help

Point e(−5, 3) and point d(−4, −3) are located on the grid. which measurement is closest to the distance between point e and point d in units? a) 6.1 units b) 6.3 units c) 6.5 units d) 6.7 units

Describe all the numbers that when rounded to the nearest thousand are 645,000

How do i do this? i don’t understand