to center two objects, you need to calculate their total width (including the gap between them),
then find the center of the screen,
then subtract half of the total width of the objects from the center, so obviously half the total width is on one side, and the other half is on the other side...
a couple things to watch out for: if you use "Scale Outer" to have your game fill the screen, then the left edge of the screen might not start at zero. So, I always calculate the center by doing:
viewportRight(0)-viewportLeft(0) / 2
you also have to factor in where the origin of the coin sprite is. If the origin is the middle of the sprite, then you have to add back in Coin.Width / 2
I made a sample because it is harder to explain than to show... click the coin to randomly generate a new number and have it center the coin and text. Note: when you start my sample, the coin and text wont be centered until you click on the coin...