I am assuming that you are using the 2 as a track matte for an image. I can only guess because you gave us no details or a screenshot of your comp with all modified properties of all layers revealed. I'm also assuming that you want to reveal the image below rather than push into it.
If that is the case then you can either make the layer containing the number 2 a 3D layer and animate the position so that it moves toward and past the camera or you can leave the layer 2D and animate the scale of the layer. You'll get a more natural look if you use the 3D trick. You might want to consider moving the anchor point of the layer to the part of the 2 that you want to be the center of the reveal. This is what a basic 3D move would look like.