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Michael Otu

Posted on • Updated on

# Python3 Programming - Exercise 4 - Arithmetic Operators

## Arithmetic Operators

Arithmetic operators are reserved symbols used for performing mathematical operations ( calculations).

## Examples

operators symbols use return type
Addition + 1 + 3 int
Subtraction - 3 - 1 int
Multiplication * 3 * 2 int
Exponent ** 3 ** 2 int
Float division / 3 / 2 float
Integer division // 3 // 2 int
Modulo % 3 % 2 int

### Note

• If one of the operands is a float, then the resulting value is casted ( converted) into a float. `Eg: 1.0 + 1 = 2.0 and 1 + 1 = 1` .
• `//` , returns the whole number part ( quotient) of the division. So, `given: 22.0 // 3 = 7.0 and 22 // 3 = 7` .
• `/` , returns the quotient and the remainder as a float, together. `Eg: 22 /3 = 7.333333333333333 and 0.25 / 0.5 = 0.5` .

# Casting

Casting means, converting or changing from one type to another. To know the type of a value, use the `type(obj)` function. `Eg: type(2) and type('2') will return <class 'int'> and <class 'str'>` respectively. Meaning that 2 is an integer and '2' is a string.

## Note

The values of x and y don't change after the casting, except that we do, `y = float(y)`.

# Practicals

write a program to evaluate and print the results of the following given that `a = 2` and `b = 5` :

• a _ (2 _ b) - 5
• 2 * (b - a) + b
1. (-(a _ b) ** 2 - (4 _ a * b) ) / ((b // a) // 3 + (16 / a / b))
2. ((a ** 2) - (b ** 2)) // ((b - a) ** 2)
3. ((a + b) % 2) - ((b % a) + 1)

# Summary

• `+, -, *, **, /, //, %` are reserved for mathematical operations.
• Rule of precedence is `(), **, *, //, /, +, -` .
• Use parentheses to change the precedence.