3. Learn Math With Python – Divisibility of Numbers
For two given numbers a and b (a > 0), a is said to be divisible by b, if b completely divides b (without leaving any remainder). For example 18 is divisible by 3.
% operator is used to find a remainder when one number is divided by another number.
3.1 Use of % Operator
For example a % b means remainder when a is divided by b.
#Accepting values num = int (input ('Enter the number whose divisibility needs to be checked: ')) div = int (input ('Enter the number with which divisibility needs to be checked: ')) #Checking divisibility if num % div == 0: print (num, 'is divisible by ', div) else: print (num, 'is NOT divisible by ', div)
3.2 Checking For Even or Odd Number
A number is called an even number if it is divisible by 2 and is called an odd number if it is not divisible by 2. For this, you’ll divide a number by 2 and find the remainder (using modulus operator %). If the remainder is 0, then the number is even, otherwise the number is odd.
Note: The remainder when a number is divided by 2 is always one of the following:
- 0 – Divisible
- 1 – Not divisible
#Accepting number num = int (input ('Enter a number: ')) #Checking for Even or Odd if num % 2 == 0: print (num, 'is Even ') else: print (num, 'is Odd ')
3.3 Counting Even & Odd Numbers
import array as arr numbers = arr.array('i', []) num = input("How many numbers do you want to enter? ") #user tells the range(optional) #iterating till user's range is reached for i in range(int(num)): n = input("Enter a value ")#asking for input of 1 value numbers.append(int(n))#adding that value to the array even = 0 odd = 0 #iterating till user's range is reached for i in range(int(num)): if numbers[i]%2 == 0: even += 1 else: odd += 1 print("Number of Even Numbers = ", even) print("Number of Odd Numbers = ", odd)