★ Christmas Cup Stacking Challenge! | Holiday STEM Activity | Winter Team Building ★Bring festive fun to your December lessons with this Christmas Cup Stacking Challenge—a holiday STEM activity that blends teamwork, problem-solving, and hands-on excitement! Students practice counting, engineering, number sense, and motor skills while exploring numbers up to 115 in a playful, Christmas-themed format. This December STEM activity is perfect for Christmas math centers, holiday parties, winter STEM