Density is a great exercise in physical science and a great exercise in math literacy. There are many resources on TpT about density and I think that that there is room for one more. The teacher could use this as a quiz, a worksheet or a test. The teacher could use this as a guided lecture. This would be a way to introduce this concept, for example, to 6th graders. Pass out the worksheet and do it together as a sort of interactive lecture.
I am using this TpT lesson to experiment with formats