Is there one iota of research to support any of the proposed remedies? In particular: kids need more word problems. Do they really? Would it make any difference

Is there one iota of research to support any of the proposed remedies? In particular: kids need more word problems. Do they really? Would it make any difference to the outcome? What is the desired outcome? One reason education isn't better is it is by and large pre-scientific. Teaching approaches are based on opinions, anecdotes and cherished beliefs, but precious little data.