How to fill the playing field with numbers?

Question

Game development

Good evening.
I'm making a game on Unity (I took the off-line roguelike tutorial as a basis).
You need to make a playing field filled with one texture (background) and random numbers on top of it.
I wrote a cycle (altered from the tutorial):

void BoardSetup()
    {
        boardHolder = new GameObject("Board").transform;

        for (int x = 0; x < columns; x++)
        {
            for (int y = 0; y < rows; y++)
            {
                GameObject toInstantiateBackground = snowTile;
                GameObject backgroundInstance = Instantiate(toInstantiateBackground, new Vector3(x, y, 0f), Quaternion.identity) as GameObject;
                backgroundInstance.transform.SetParent(boardHolder);
                GameObject toInstantiateDigit = digitTiles[Random.Range(0, digitTiles.Length)];
                GameObject digitInstance = Instantiate(toInstantiateDigit, new Vector3(x, y, 0f), Quaternion.identity) as GameObject;
                digitInstance.transform.SetParent(backgroundInstance.transform);
            }
        }
    }

I get the following result:

I also tried to set boardHolder as the parent element in the last line, but the result is the same.

Answer 1

Are numbers a separate entity? Maybe the layer is not specified.