Top off your 100th Day of school celebration with this fun and easy coordinate geometry activity that uses a 100-square grid. Give each student a copy of the 100th Day Reproducible (PDF), a pencil, and a ruler. Help students locate the first ordered pair (2, 9) on the grid. Then direct them to plot the point on the grid that corresponds with the next ordered pair (3, 6). Next, they use a ruler to connect the two points. Have students continue plotting and connecting points to reveal the hidden picture-a festive party hat!