I was a consultant math teacher at the elementary level and found too often that teachers had a poor understanding of these concepts. Most did not like teaching math and failed to use visual and hands-on materials to help students understand the connection between the various ways to represent rational numbers. They all were receptive to guidance in how to teach these concepts and I suspect learned some things themselves. We need to do more at the local level to assist teachers and be sure they are conveying the same accurate message to students.