2 columns of 4 simple story problems each. Fold the paper in half lengthwise, so that only 4 problems are visible. Students then do a Stand Up, Hand Up, Pair Up and ask their partner "Can you help me?". That partner is in charge of helping the student solve one of the four problems. After each have solved a problem for the other, they Stand Up, Hand Up, and Pair Up to find a new partner. They then repeat the process.
This "Give One, Get One" activity is a great strategy to get students explaining their thinking and challenging one another. The second set of 4 problems is then for the students to complete independently (or to continue with partners if you so choose!).