This resource focuses on teaching students how to accurately round whole numbers up to 1,000 to the nearest 10s and 100s using place value reasoning. It outlines a clear rounding rule, where students determine whether to round up or down based on the digit immediately to the right of the target place value. The lesson includes a hands-on game, the 'Card Sort Challenge', where students draw number cards, identify the target place value, and sort them into 'Round Up' or 'Round Down' piles while working with a partner. Additional activities involve visualizing numbers on a number line and reflective writing that encourages deep thinking about why the digit '5' prompts rounding up. The lesson also contains analysis of specific numbers, challenges in rounding, and justification of reasoning, fostering comprehensive understanding of rounding concepts.