# C Program to Find the Remainder Without Using Modulo Operator

Howdy readers, today you will learn how to write a C program to find the remainder without using the modulo operator.

In the C Programming language, the modulus operator (%) is used to find the remainder. For example, 15 % 4 => 3 where 3 is the remainder.

But in this program, we will find the remainder without the modulo operator. We will be using the following methods to find the remainder:

1. Using Mathematics
2. Using Repeated Subtraction

So, without any delay, letâ€™s begin this tutorial.

## C Program to Find the Remainder Without Using Modulo Operator

C Program

```// C Program to Find the Remainder Without Using Modulo Operator
#include <stdio.h>
int main(){
int a, b, rem;

// Taking Input
printf("Enter the first number: ");
scanf("%d", &a);
printf("Enter the second number: ");
scanf("%d", &b);

// Remainder
rem = a - (a/b) * b;

// Display Remainder
printf("The remainder is: %d", rem);

return 0;
}
```

Output

```Enter the first number: 20
Enter the second number: 3
The remainder is: 2
```

Explanation

```    int a, b, rem;
```

We have created three integer variables to store the values of dividend (a), divisor (b) and the remainder (rem).

```    printf("Enter the first number: ");
scanf("%d", &a);
printf("Enter the second number: ");
scanf("%d", &b);
```

The user is asked to input the dividend and divisor. The dividend and divisor are stored in the a and b variables respectively.

```    rem = a - (a/b) * b;
```

Now, we used the mathematical formula to find the remainder.

Dividend = (Quotient x Divisor) + Remainder

It can also be written as,

Remainder = Dividend – (Quotient x Divisor)
rem = a – ((a/b) * b)

where,

• a is the dividend
• b is the divisor
• rem is the remainder

Note: a/b returns quotient.

The computed remainder is stored in the rem variable.

```    printf("The remainder is: %d", rem);
```

In the end, we print the value of the remainder on the screen using the printf() function.

## C Program to Find the Remainder Using Repeated Subtraction

C Program

```// C Program to Find the Remainder Using Repeated Subtraction
#include <stdio.h>
int main(){
int a, b, r;

// Taking Input
printf("Enter a dividend: ");
scanf("%d", &a);
printf("Enter a divisor: ");
scanf("%d", &b);

// Remainder Using Repeated Subtraction
while (a > b){
a = a - b;
}

// Store Remainder Value
r = a;

// Print Remainder
printf("The remainder is: %d", r);
return 0;
}
```

Output

```Enter a dividend: 10
Enter a divisor: 3
The remainder is: 1
```

Explanation

```    while (a > b){
a = a - b;
}
```

We used a while loop to find out the remainder.

Suppose the user enters a = 10 and b = 3. Then,

• 1st While Loop Iteration:
• while (10 > 3), the condition is True.
• a = a – b => 10 – 3 => 7.
• 2nd While Loop Iteration:
• while (7 > 3), the condition is True.
• a = a – b => 7 – 3 => 4.
• 3rd While Loop Iteration:
• while (4 > 3), the condition is True.
• a = a – b => 4 – 3 => 1
• 4th While Loop Iteration:
• while (1 > 3), the condition is False, so the loop terminates. The value of a becomes 1.
```    r = a;
```

The leftover value is the remainder which is stored in the r variable.

## Conclusion

Today you learned how to write a C program to find the remainder without using the modulo operator (%).

You also learned how to find the remainder using

1. Using Simple Mathematics
2. Using Repeated Subtraction

If you have any queries, comment them down in the comment section.