Engage your students by letting them solve a puzzle while they are working with the basic operations of adding, subtracting, multiplying, and dividing integers. Positive and negative numbers are included, and larger numbers are used to help strengthen mental math skills. As they evaluate various problems, each numerical answer is associated with a letter. These letters get filled into spaces which will solve a riddle upon completion of all problems. This activity is designed to encourage partner work, switching partners with each new problem. Directions are included!