These games were created to reinforce instruction of 10 plus and minus as well as 100 plus or minus of any number within 1000. You can teach the game and allow students to play together for practice. You can also play the game with individuals to assess their understanding of the concepts. I also have provided an activity sheet if you want a hard copy of their thinking. This activity meets the 2nd grade Common Core standard to mentally add 10 or 100 to a given number 100 - 900, and mentally subtract 10 or 100 from a given number 100 - 900. [2-NBT8] I made them with pumpkins so you can use them all fall.
Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.