Write your multiplying by powers of 10 recursive function in

multiply :: Int -> Int -> Int
multiply n 0 = n
multiply n p = read (prefix ++ suffix)
  where prefix = show n
        suffix = replicate p '0'

>>54906644

fn mul(a : u64, b : i32, acc : u64) -> u64 {
    if b == 0 {
        acc
    } else {
        mul(a, b - 1, acc + a)
    }
}

fn e10(b : u64, e : i32) -> u64 {
    if e > 0 {
        e10(mul(b, 10, 0), e - 1)
    } else {
        b
    }
}

>>54907000
got damn rust is ugly

>>54906779
Just realised, I don't need the first clause, if I'm not doing recursion.

r8

double MultiplyByTen(double number, int index)
{
    if (index == 0) return number;
    
    if (index < 0) throw new ArgumentOutOfRangeException(nameof(index));

    double originalValue = number;

    for (int i = 0; i < 9; i++)
    {
        number += originalValue;
    }

    return MultiplyByTen(number, index - 1);
}

>>54906644

#!/bin/bash
function multiplyBy10() {
    # check if both args are integers
    intTest='^[0-9]+$'
    if [[ ${1} =~ $intTest ]] && [[ ${2} =~ $intTest ]]
    then
        printf '%s' ${1}
        printf '0%.0s' {1..${2}}
    fi
}

>>54907240
I think this would be enough.

for (int i = 0; i < 9; i++) number += originalValue;

>>54907353
That's the same thing. If you wanna code golf you can just reduce it to

double m(double n, int i)
{
    if (i<=0) return n;
    double o=n,k=0;
    for (;k++<9;)n+=o;
    return m(n, i-1);
}

File: 1396927874103.jpg (155KB, 1031x882px) Image search: [Google]

155KB, 1031x882px

function powers(x, n) {
     return eval(x + "e" + n)
}

>>54907728
Kekimus maximus

int Multiply10(int n, int x)
{
string number = itoa(n);
char zero='0';
for(int i =0;i<x;i++)
string. append(zero) ;
return atoi(number. c_str());
}

>>54908461
crap, should be number.append(zero);

>>54908461
disgusting

>>54906644

Recursive

function mb10(a, b) {
  return (b < 1) ? a : mb10(a*10, b-1)
}

What I would actually do

function mb10(a, b) {
  return parseInt(`${a}e${b}`)
}

File: 1405808156512.jpg (139KB, 600x404px) Image search: [Google]

139KB, 600x404px

>>54908798
>Use only addition