Dharani Tech Edu Hub

Number Programs in C

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Introduction

Number programs help in building strong logic and problem-solving skills in C programming.

👉 These programs involve mathematical operations and conditions.

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Why Learn Number Programs?

• ✔ Improve logical thinking
• ✔ Useful in interviews
• ✔ Practice loops & conditions
• ✔ Strengthen programming basics

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1. Check Even or Odd

#include <stdio.h>

int main() {
    int num = 10;

    if (num % 2 == 0)
        printf("Even");
    else
        printf("Odd");

    return 0;
}

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Output

Even

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2. Find Factorial

#include <stdio.h>

int main() {
    int i, n = 5, fact = 1;

    for (i = 1; i <= n; i++) {
        fact = fact * i;
    }

    printf("Factorial = %d", fact);

    return 0;
}

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Output

Factorial = 120

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3. Check Prime Number

#include <stdio.h>

int main() {
    int n = 7, i, flag = 1;

    for (i = 2; i <= n / 2; i++) {
        if (n % i == 0) {
            flag = 0;
            break;
        }
    }

    if (flag == 1)
        printf("Prime");
    else
        printf("Not Prime");

    return 0;
}

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Output

Prime

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4. Reverse a Number

#include <stdio.h>

int main() {
    int num = 123, rev = 0;

    while (num != 0) {
        rev = rev * 10 + num % 10;
        num = num / 10;
    }

    printf("Reverse = %d", rev);

    return 0;
}

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Output

Reverse = 321

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5. Check Palindrome

#include <stdio.h>

int main() {
    int num = 121, temp, rev = 0;

    temp = num;

    while (num != 0) {
        rev = rev * 10 + num % 10;
        num = num / 10;
    }

    if (temp == rev)
        printf("Palindrome");
    else
        printf("Not Palindrome");

    return 0;
}

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Output

Palindrome

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6. Sum of Digits

#include <stdio.h>

int main() {
    int num = 123, sum = 0;

    while (num != 0) {
        sum += num % 10;
        num /= 10;
    }

    printf("Sum = %d", sum);

    return 0;
}

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Output

Sum = 6

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Number Programs Table

Program	Purpose
Even/Odd	Check number type
Factorial	Multiply sequence
Prime	Check prime number
Reverse	Reverse digits
Palindrome	Check same forward/backward

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Important Notes

• Use loops properly
• Understand number logic
• Practice different problems

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Common Mistakes

• ❌ Wrong loop conditions
• ❌ Incorrect variable usage
• ❌ Missing logic steps

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Pro Tips

• ✔ Practice daily
• ✔ Break problem into steps
• ✔ Try variations
• ✔ Focus on logic

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Conclusion

Number programs are essential for building strong programming logic. They help in understanding conditions and loops deeply.

Practice regularly to improve your coding skills.

👉 This article is part of Dharani Tech Edu Hub — where learning programming is made simple and practical.