Use the or to create your own problem adding four 2-digit numbers together. Example: 21+13+32+11=. Solve your addition problem. Create and solve at least 10 problems. Bonus Challenge: Use the to write a word problem to go along with your addition problem. Example: John had 21 blue pencils, 13 red pencils, 32 yellow pencils, and 11 green pencils. How many pencils does John have altogether?