Basic Arithmetic and Operator Precedence
You'll use arithmetic operators constantly in Python. This chapter focuses on the most common ones and how precedence determines evaluation order.
Main Operations
Addition (+)
Addition is used to sum two or more numbers.
1print(5 + 3) # output: 8
Subtraction (-)
Subtraction finds the difference between two numbers.
1print(10 - 4) # output: 6
Multiplication (*)
Multiplication calculates the product of two numbers.
1print(6 * 7) # output: 42
Division (/)
Division returns the quotient of two numbers.
1print(20 / 5) # output: 4.0
Exponentiation (**)
Exponentiation is used to raise a number to the power of another number. In Python, this is done using the ** operator.
1print(2 ** 3) # output: 8
Operator Precedence
When multiple operators appear, Python evaluates them in this order (highest β lowest among arithmetic):
**;- Unary
+and-(sign); *,/;+,-.
Parentheses always win and make intent explicit. Exponentiation ** is right-associative.
123456789print(2 + 3 * 4) # 14 (multiplication before addition) print((2 + 3) * 4) # 20 (parentheses change the order) # Exponentiation binds tighter than unary minus print(-3 ** 2) # -9 (equivalent to -(3 ** 2)) print((-3) ** 2) # 9 # Right-associative exponentiation print(2 ** 3 ** 2) # 512 (2 ** (3 ** 2))
- Prefer parentheses in anything nontrivial; readability > cleverness.
- Remember
/always yields a float (even if divisible).
1. What value will this code output?
2. Which expression evaluates to 64?
3. What value will this code output?
Thanks for your feedback!
Ask AI
Ask AI
Ask anything or try one of the suggested questions to begin our chat
Awesome!
Completion rate improved to 5Basic Arithmetic and Operator Precedence
Swipe to show menu
You'll use arithmetic operators constantly in Python. This chapter focuses on the most common ones and how precedence determines evaluation order.
Main Operations
Addition (+)
Addition is used to sum two or more numbers.
1print(5 + 3) # output: 8
Subtraction (-)
Subtraction finds the difference between two numbers.
1print(10 - 4) # output: 6
Multiplication (*)
Multiplication calculates the product of two numbers.
1print(6 * 7) # output: 42
Division (/)
Division returns the quotient of two numbers.
1print(20 / 5) # output: 4.0
Exponentiation (**)
Exponentiation is used to raise a number to the power of another number. In Python, this is done using the ** operator.
1print(2 ** 3) # output: 8
Operator Precedence
When multiple operators appear, Python evaluates them in this order (highest β lowest among arithmetic):
**;- Unary
+and-(sign); *,/;+,-.
Parentheses always win and make intent explicit. Exponentiation ** is right-associative.
123456789print(2 + 3 * 4) # 14 (multiplication before addition) print((2 + 3) * 4) # 20 (parentheses change the order) # Exponentiation binds tighter than unary minus print(-3 ** 2) # -9 (equivalent to -(3 ** 2)) print((-3) ** 2) # 9 # Right-associative exponentiation print(2 ** 3 ** 2) # 512 (2 ** (3 ** 2))
- Prefer parentheses in anything nontrivial; readability > cleverness.
- Remember
/always yields a float (even if divisible).
1. What value will this code output?
2. Which expression evaluates to 64?
3. What value will this code output?
Thanks for your feedback!
