sirlink99 56 Practically a Master Poster

Hello. I am designing a calculator app as part of a project. I have all the buttons inserted in the correct order. My problem is that the last column of buttons horizontally fills up the rest on the unused screen. As the device size scales, the more and more the buttons strech. I would like it so that all the buttons take on the excess space evenly. What would be the easiest way to accomplish this? What commands should I be looking at. If you need the code I can post it later, however I would prefer not to post it. Thank you for your help.

Here are 2 screenshots:
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