why is there an unexpected maths result from a float calculation?

[snippsat]

Basic Answers
For financial calculation use decimal module.

from decimal import Decimal

pennies = input('Enter pennies: ')
dollars = Decimal(pennies) * Decimal('.01')
print(f'{pennies} pennies are worth ${dollars:.2f} in dollars')
print(dollars) 

Output:
Enter pennies: 35
35 pennies are worth $0.35 in dollars
0.35