In the program below, we’ve used the arithmetic addition operator (+) to add two numbers.

Source Code

2. # This program adds two numbers
4. num1 = 1.5
5. num2 = 6.3
7. # Add two numbers
8. sum = float(num1) + float(num2)
10. # Display the sum
11. print('The sum of {0} and {1} is {2}'.format(num1, num2, sum))

Output

The sum of 1.5 and 6.3 is 7.8

Changing this operator, we can subtract (-), multiply (*), divide (/), floor divide (//) or find the remainder (%) of two numbers.

Source Code: Add Two Numbers Provided by The User

1. # Store input numbers
2. num1 = input('Enter first number: ')
3. num2 = input('Enter second number: ')
5. # Add two numbers
6. sum = float(num1) + float(num2)
8. # Display the sum
9. print('The sum of {0} and {1} is {2}'.format(num1, num2, sum))

Output

Enter first number: 1.5
Enter second number: 6.3
The sum of 1.5 and 6.3 is 7.8

In this program, we asked the user to enter two numbers and this program displays the sum of two numbers entered by user.

We use the built-in function input() to take the input. input() returns a string, so we convert it into number using the float() function.

Alternative to this, we can perform this addition in a single statement without using any variables as follows.

1. print('The sum is %.1f' %(float(input('Enter first number: '))+float(input('Enter second number: '))))

Although this program uses no variable (memory efficient), it is not quite readable. Some people will have difficulty understanding it. It is better to write clear codes. So, there is always a compromise between clarity and efficiency. We need to strike a balance.