There's has to be a cleaner way to do this with rspec and ruby

rspecparams.rb

[ ["1,2",3], ["1,3",4] ].each do |arr|
    it "'s add method should return the sum of multiple numbers" do
      StringCalc.new.add(arr[0]).should == arr[1]
    end
 end

I'd do something similar, but use example in place of it.

context "when adding numbers" do
  {"1,2" => 3, "1,3" => 4}.each do |input, expected|
    example input do # input is already a String, and no need to add surrounding text
      StringCalc.new.add(input).should == expected
    end
  end
end