Java implementation of Radix Sort assuming base 10

Radix Sort 1

private static int[] radixSort(int[] unsortedArr, int digits){
		for(int i = 1; i <= digits; ++i){
			unsortedArr = countSort(unsortedArr, 10, (int)Math.pow(10, i));
		}
		return unsortedArr;
	}
	
	private static int[] countSort(int[] unsortedArr, int base, int digit){
		int[] keyArray = new int[base];
		
		for(int i = 0; i < unsortedArr.length; ++i)
			keyArray[(unsortedArr[i] / (digit/base)) % base]++;
		for(int j = 1; j < keyArray.length; ++j)
			keyArray[j] += keyArray[j-1];
		 
		int[] sortedArr = new int[unsortedArr.length];
		for(int i = unsortedArr.length-1; i >= 0; --i){
			sortedArr[keyArray[(unsortedArr[i] / (digit/base)) % base]-1] = unsortedArr[i];
			keyArray[(unsortedArr[i] / (digit/base)) % base] -= 1;
		}
		return sortedArr;
	}