The type of scaling that you have done right now is non-uniform scaling because you stretched the object along a single axis, causing the object's shape to be altered. The other kind of scaling is called uniform scaling in Maya where all the three dimensions of the object changes equally at the same time.

In order to perform Uniform Scaling in Maya, click and drag on the pale yellow colored small box present at the center of the cube object. Our cube will start to shrink or expand based on the direction of your movement in Maya. Since the mode of scaling is uniform, all the axes will scale in equal amounts and the shape of the object remains same, though the size changes in Maya.

NOTE: You can Undo any action in Maya by pressing 'z' . Please note that the z is lowercase. So if you need to undo, make sure that the caps-lock on your keyboard is not ON. For performing a Redo in Maya press Shift+z, or keeps your caps-lock on and press z. (In short z results in undo and Z results in redo)

You can perform multiple undos and redos by pressing the respective keys repeatedly.

Inside the Channel Box / Layer Editor panel, you will see three similar tab buttons along the panel's top left corner as shown . Click on the left most one. It displays the Channel box alone (The second button shows the layer editor alone and the third button displays both the channel box and layer editor). The channel box appears as shown in the figure to the right in Maya.

You can see the Translate/Move co-ordinate values, Rotation angles and Scale ratios in the channel box in Maya.