Finally, two fellow teachers and I created a song that 10 years later is still helping my students be successful with rounding.
In addition to the song, I developed a technique that has helped countless groups of students master the difficult concept of rounding numbers. This method helps students remember what place they are rounding to, focus on the number that tells you whether to go up or go down, and how to remember that everything turns to zeros.
I developed a packet to teach others this method. It includes notes for teachers, the unique song that we created all those many years ago, several printables on rounding to the nearest ten, hundred, and thousand's place, a Rounding I Have:Who Has game, and a list of Rounding Resources including videos, websites, and games.
See a preview of it at my TpT store.
I also have several estimating and rounding PowerPoint Presentations and a multiplying by multiples of tens and hundreds at my store and on my Facebook page.