Also, the Trachtenberg system includes some specialised methods for multiplying small numbers between 5 and 13.Some of the algorithms Trachtenberg developed are ones for general multiplication, division and addition.

COMING SOON!

```
/**
* Problem : Muliply a number by 7 by using bit manipulation.
* Approach : left shift n by 3 --> 8n
* Therefore 7n = 8n - n;
*/
#include <iostream>
int multiply_by_7( int number )
{
return ((number << 3) - number);
}
int main()
{
std::cout << "Enter a number:";
int num;
std::cin >> num;
std::cout << "7 x " << num << " = "
<< multiply_by_7(num) << std::endl;
return 0;
}
```