Spriteを変更する
Assets/Resources/Imageフォルダ内に[Sprite Mode] SingleのImage1.pngと[Sprite mode] Multipleのnumber.pngを用意して number.pngをSliceする
// Sprite Mode Single
Sprite sprite = Resources.Load<Sprite>("Image/Image1");
image.sprite = sprite;
// Sprite mode Multiple
Sprite[] sprites = Resources.LoadAll<Sprite>("Image/number");
sprite = sprites.Where(x => x.name == "number_1").FirstOrDefault();
image.sprite = sprite;