This product can be used as a center activity. It is differentiated into 3 different groups: red, yellow, and blue. The red level has sums to 20, the yellow level has sums to 100, and the blue level has sums to 1,000. All three levels come with their own set of directions, activity cards, and true/false cards colored to match each level. Each level has 12 activity cards each. Included is a reproducible recording sheet and answer sheet for each level. I created this activity because I found that this skill was very difficult for my students to master. Enjoy! Thank you in advance for positive feedback!