A great reference tool for students to place in their notebooks vertically. First, my students and I reviewed the places and values of each space on the chart. Then, we discussed how every three digits makes a period. I directed my students to shade in each period with a different crayon color. I read a number (population of the US) out loud which students wrote in the chart, then asked them "What might this number represent?" After hearing student responses I revealed it was the population of the US. Students glued the chart into their notebooks and often refer back to it.
Photocopy, then cut in half.