This video serves as a comprehensive "Mastery Check" for 5th-grade students learning to round decimals. Hosted by "Mr. J," the video presents a self-contained assessment consisting of ten specific problems where students must round decimals to the underlined place value (tenths, hundredths, or whole numbers). The format encourages active participation by asking viewers to pause the video, solve the problems independently on paper, and then resume to check their work. The content covers a variety of rounding scenarios, ranging from straightforward rounding to more complex cases involving carrying over numbers (e.g., rounding 9.9 to 10). It specifically targets common stumbling blocks, such as rounding numbers where the digit remains the same or when rounding up affects the next place value. The video provides immediate feedback with handwritten solutions and brief verbal explanations for each problem. This resource is an excellent tool for formative assessment, independent practice, or homework review. Teachers can use it to gauge student proficiency at the end of a unit on decimals. The "pause-and-practice" structure allows for self-paced learning, making it ideal for differentiation in the classroom or for students who need additional reinforcement at home. The video concludes with a scoring guide, helping students self-assess their mastery level.