The problem types most appropriate for students at this level include: Common Addition and Subtraction Problem Types - Join (Result Unknown): Sue had 4 pennies. Josh gave her 2 more. How many pennies does Sue have altogether?; Separate (Result Unknown): Sue had 8 pennies. She gave 5 pennies to Josh. How many pennies does Sue have now?; Part-Part-Whole (Whole Unknown): Josh has 4 red balloons and 3 blue balloons. How many balloons does he have?; Part-Part-Whole (Both Parts Unknown): Josh has 5 balloons. Some of them are red and some of them are blue. How many balloons can be blue and how many can be red?