This activities has the students use the weight of plain M&Ms and peanut butter M&Ms to write and solve a system of linear equations. Each group of students is given a sealed bag with a mixture of plain M&Ms and peanut butter M&Ms. The bags are labelled with the total number of M&Ms in the bag. There are also 3 reference bags: a bag of 50 plain M&Ms, a bag of 50 peanut butter M&Ms and an empty bag. Using a scale the students will use the reference bags and their group bags to construct their equations. Then using prior knowledge they will solve the system using the elimination method or the substitution method. This activity can be adapted for any two different weight objects to adjust for allergies or student interests.