This monster-themed bundle includes five different worksheets, with increasing difficulty. This is great for differentiated learning, or for math centers, as well as for general practice. Each worksheet has a riddle that the student can find the answer to by solving the math problems. Included in this bundle are 1) double digit addition, 2) double digit addition with carrying, 3) addition within hundreds, 4) double digit subtraction without borrowing, and 5) double digit subtraction with borrow