Unity Issue with Vector3 and Transform

I am currently running into this error:

Cannot implicitly convert type UnityEngine.Vector3 to Unity.Engine.Transform

I am not sure on how to fix this issue because, here's the code where the issue is occurring.

target = pickedNumber.transform.position;
ball.transform.position = Vector3.MoveTowards(transform.position, target.position, step);

Here's the for loop that contains the above snippet:

float waitTime = 8;
    float step = speed * Time.deltaTime * 2;

    yield return new WaitForSeconds (waitTime);

    for (int i = 0; i <= 19; i++) {
        //Finding Game Objects
        numbers = GameObject.FindGameObjectsWithTag ("num");
        ball = GameObject.FindGameObjectWithTag ("ball");

        //Picking the random cube
        index = Random.Range (0, numbers.Length);
        pickedNumber = numbers [index];

        //Moving ball to cube
        target = pickedNumber.transform.position;
        ball.transform.position = Vector3.MoveTowards(transform.position, target.position, step);

        //Pause here
        yield return new WaitForSeconds (waitTime);

        //Ball Returns to position
        ball.transform.position = new Vector3 (0, 0, 0);
    }