In this Halloween-themed math investigation, students will figure out how much candy can be added together to make a sum of 10. They will start with two types of candies and identify complements of 10. For example: 3 candy corns + 7 tootsie rolls =10 total Halloween candies. The worksheets are differentiated so that higher level students can identify complements of 10 using three types of candies. They can also identify complements of 20 using two types of candies. This is great for kindergarten and first grade students who are working on identifying quantities, counting, addition, and cutting with scissors! I also included my lesson plan with this activity. Enjoy!