When my students come to me, they aren't expected to read numbers over the thousands place. It is my job to get them to read numbers up to the millions place (and decimals to the thousandths, but more to come on that later).
A good way to review this (and have some quiet time) is to write numbers from the hundreds up to the millions on pieces of paper. Hand one out to each student (I give the smaller numbers to students who are struggling-but they don't know this obviously).
They are to line up in front of the room from smallest to largest (or the other way-that doesn't matter) without speaking. If they speak, they are "out". If they aren't in the right order, you just tell them something is wrong, but don't point out who it is. Have them keep trying until they are correct. Once they are in order, each person takes a turn reading his or her number. Do this several times, each time giving the student a new number to line up with and read.