Aligned to the 7th grade common core standards, this is an activity that can be done by an individual or a cooperative group. It begins with a person having a credit card with a balance. There are a series of questions that follow where students have to constantly figure out what the ending balance is. Students need to write a math problem for each question and explain what word makes the number a negative or a positive (example (not from the activity, but easy to get what it is): Sally has $30 and spends $40. What is the balance on her card? Students will write + 30 and explain that "has" tells us 30 is positive; then - 40 and explain that "spends" tells us 40 is negative; then 30 + -40 = -10 to show how they know the final balance). The ultimate goal is to figure out what the final balance on the card is after 17 questions. Comes with the typed activity as well as the student work page. No number line included, though students should use one as they are going through the problems.