Looking for a low-prep, standards-focused activity that will keep your students engaged and learning in the month of February? This STEM challenge is a great community builder in the classroom and has students practicing skills including teamwork, fine motor practice, data collection, and measurement. My students could have stacked hearts for hours! This challenge can be used as a quick 30 minute math lesson, or could be extended for a whole afternoon of heart-themed activities and mini-lessons.