CS50 week 6 PSET cash doesn't follow through while loop properly

I'm trying to implement a program that takes the value of change required and returns back the least the amount of coins required (25 cents,10 cents, 5 cents, and 1 cent) to give back that change. What I've opted for is the user to input the correct format(I've done error handling on this end which works) and this value of change will be passed through a while loop where the value of change will be compared to see if it is greater than or equal or to one of thee aforementioned coin values. The integer number of coins required is calculated and added to a running total of coins, and the value of change required is updated to remove the new total of change given back from the coins calculated from the existing change. The loop terminates once the change reaches 0:

<!-- begin snippet: js hide: false console: false babel: false -->

<!-- language: python -->

import math
while True:
        try:
            changeOwed = float(input("Change owed:"))
            while changeOwed < 0:
                changeOwed = float(input("Change owed:"))
            break
        except ValueError:
            continue


    coinCount = 0
    while changeOwed >float(0):
        if changeOwed >= 0.25:
            quartersNeeded = math.floor(changeOwed/0.25)
            coinCount = coinCount + quartersNeeded
            changeOwed = changeOwed - (quartersNeeded*0.25)
        elif changeOwed >= 0.10:
            dimesNeeded = math.floor(changeOwed/0.1)
            coinCount = coinCount + dimesNeeded
            changeOwed = changeOwed - (dimesNeeded*0.1)
        elif changeOwed >= 0.05:
            NickelsNeeded = math.floor(changeOwed/0.05)
            coinCount = coinCount + NickelsNeeded
            changeOwed = changeOwed - (NickelsNeeded*0.05)
        else:
            PenniesNeeded = math.floor(changeOwed/0.01)
            coinCount = coinCount + PenniesNeeded
            changeOwed = changeOwed - (PenniesNeeded*0.01)
        break
    print(coinCount)

<!-- end snippet -->

The problem here is if I test the program with values that aren't fully divisible by any of the aforementioned coin values (such as 0.4,4,.2,0.15,etc..) the program only returns the coin count for the largest coin value (i.e. 4.2 returns 16 coins (all of which are 0.25) but neglects the 2 coins that are 0.1. Or 0.15 returns one coin (the 0.1) while forgetting about the remaining 0.05. If I remove the break the statement the program only works with values that are fully divisible by any of the coin values, but enters a non-terminating loop for other values. How do I fix this, and why has this happened?

one issue was doing floor division with floats, for example 0.15 gave 1 dime and 4 pennies. multiplying everything by 100 to do floor division by integers seems to fix the problem.
guess it has to do with Floating Point Math.

def make_change(change_owed=-1):
    coins = {}

    while change_owed < 0:
        try: change_owed = float(input('Change owed:'))
        except ValueError: print('invalid amount, try again')
    
    print('change owed: %.2f' % change_owed)
    
    change_owed *= 100
    
    coins['quarters'] = change_owed // 25
    change_owed -= coins['quarters'] * 25
    coins['dimes'] = change_owed // 10
    change_owed -= coins['dimes'] * 10
    coins['nickles'] = change_owed // 5
    change_owed -= coins['nickles'] * 5
    coins['pennies'] = change_owed

    print('total coins:', int(sum(coins.values())))
    for k, v in coins.items():
        if v: print('%11s:' % k, '%d' % v)

for i in (4.20, 0.69, 0.42, 0.2, 0.15):
    print('-' * 17)
    make_change(i)

output:

-----------------
change owed: 4.20
total coins: 18
   quarters: 16
      dimes: 2
-----------------
change owed: 0.69
total coins: 8
   quarters: 2
      dimes: 1
    nickles: 1
    pennies: 4
-----------------
change owed: 0.42
total coins: 5
   quarters: 1
      dimes: 1
    nickles: 1
    pennies: 2
-----------------
change owed: 0.20
total coins: 2
      dimes: 2
-----------------
change owed: 0.15
total coins: 2
      dimes: 1
    nickles: 1