I’ve found that with my 4th grade kiddos, sometimes it just takes a few reminders that they need to attend to the text to read it “just as the author wrote it”. Stopping them when they start to make those insertions/substitutions and asking them to look carefully as they reread seems to make them realize the errors they’ve made. I won’t say it ALWAYS works, but it does help some of the kids.

Something I have done before to help readers hear their errors, either in accuracy or reading rate, is recording their reading and then having them listen to themselves read the section of text while reading along in their heads. Their faces are always priceless! Usually it helps the students see the errors they are making and usually they had no idea they were making them or claim “well, I fixed it in my head”.