Question

Can anyone tell me how 665.25 - 630.75 become 34.50

Answer 1

if you break it down into stages it flows logically and clearly. Try minusing starting with the largest number (or the smallest- however you prefer):

665.25 - 600 = 65.25

65.25 - 30 = 35.25

35.25 - 0.75 = 34.50

Final answer is: 34.50

Answer 2

665.25
-630.75

34.50

you do exactly like regular subtraction, just line up the numbers from the behind the decimal but make sure they line up.
another way you could do it is pretend the decimal isn’t there and just regularly subtract and add the decimal back at the end.