This resource focuses on counting backwards using a set of 100 marbles as a context for learning. Students are encouraged to utilize a number line to track their count as they remove marbles, reinforcing number sequencing skills. The activity includes a 'Sequence Check' where students fill in missing numbers in a backward counting sequence, as well as a 'Star Challenge' which prompts them to calculate a new total after removing a set amount of marbles. This hands-on approach combines visual aids with practical math problems to enhance understanding and engagement.