There are 171 different addition problems that can be used with the Base 10 Blocks. There are 36 different addition problems that don't use regrouping. Another 36 that the student must regroup from the ones to the tens spot. There are also 36 problems that regroup from tens to 100's and another 36 problems that regroup from 100 to 1000. There is also a mixed group of addition problems. Normally I only give 2 math problems a day. The color of the numerals corresponds with what is used in the Montessori Method. This can also be used with the Montessori Numerals that are different colors.