Numeric values (int and float behavior) in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the difference between int and float in Python?

int represents whole numbers without decimals, like 5 or -3.

float represents numbers with decimals, like 3.14 or -0.001.

beginner

What happens when you divide two integers using / in Python?

The result is always a float, even if the division is exact.

Example: 4 / 2 gives 2.0, not 2.

beginner

How can you convert a float to an int in Python?

Use the int() function. It removes the decimal part (truncates).

Example: int(3.9) becomes 3.

beginner

What is the result of int(3.9999) and why?

The result is 3 because int() cuts off the decimal part without rounding.

intermediate

Why can floating point numbers sometimes give unexpected results in calculations?

Because floats are stored in a way that can’t exactly represent some decimal numbers, small rounding errors can happen.

Example: 0.1 + 0.2 might not exactly equal 0.3.

What type does the expression 5 / 2 return in Python?

A bool

B int

C string

D float

Division with / always returns a float, so 5 / 2 is 2.5.

What does int(7.8) return?

A 7

B 8

C 7.8

D Error

int() truncates the decimal part, so 7.8 becomes 7.

Which of these is a valid float number in Python?

A 3

B "3.0"

C 3.0

D 3,0

3.0 is a float. 3 is an int, "3.0" is a string, and 3,0 is invalid syntax.

What is the output of 0.1 + 0.2 == 0.3 in Python?

A True

B False

C Error

D None

Due to floating point precision, 0.1 + 0.2 is not exactly 0.3, so the expression is False.

How do you convert an integer 5 to a float?

A float(5)

B int(5)

C str(5)

D bool(5)

float(5) converts the integer 5 to the float 5.0.

Explain the difference between int and float types in Python and how division behaves with these types.

Think about whole numbers vs numbers with decimals and what happens when you divide.

Describe why floating point numbers can cause unexpected results in calculations and how Python stores these numbers.

Consider how computers store decimal numbers in binary.