How to add a digit to text value? dont do math SOLVED

I want to add a digit to a textbox/stringvalue. I mean I don't want to do math like 1+1=2 but just get the current number like 1 and add to it 1 so the script would change text value to 11 (Yes, I didn't know the concatenation)

script.Parent.MouseButton1Click:connect(function(buy)
local view = script.Parent.Parent.Parent.SUMA.P12.Text

	if view == 0 then
	wait(1) -- just nothing
	elseif view > 0 then 
	-- there i need that function so to add a digit in text
	
	wait(1)
	end

end)

Well, I'm new to Lua programming.

You could do x * 10 + y, this would effectively add a digit to your value.

function addDigit(x,y)
	return x * 10 + y
end
print(addDigit(5,7))

print(addDigit(234,8))

Output:

57

2348