Book & CD. This new enhanced edition of Addition Unplugged pairs the audio CD (teaching addition facts to 18) with a workbook filled with activities and exercises reinforcing what has been learned in the songs. While the focus of this learning kit is the teaching of addition, supporting activities also cover a variety of strands of the new Common Core Curriculum for Mathematics including: the commutative and associative properties of addition, finding missing addends, measuring length, telling and writing time, organizing, representing and interpreting data and understanding basic shapes and fractions.