How to make a simple calculator app?

I need to make a simple calculator app and I don’t know what blocks to use store the numbers and operators. In most guides they use “variables” but I don’t think that works. If anyone tells me how that would be great also if someone already has a finished simple calculator app I could just look at the blocks and learn too. Anything would be appreciated.

You can find several calculator examples in the gallery of App Inventor…

You also can try a search in the communities…
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