The race is on! This is a great unit to differentiate addition strategies. Students can use the "key" cards to practice addition strategies at their own pace. There are "key" cards for plus zero, counting on one, counting on two, doubles, near doubles, make ten, the last six, combos of 5, combos of 10, and ten & some more. The unit covers the common core mental math standards in K-2. Students are motivated to finish their race to addition by tracking their progress on a race track and receiving awards as they master strategies. This unit can be used during math centers or as students complete work throughout the day. I purchased $0.99 key chains (packs of 12) to use with this unit. The packet contains more information on where you can purchase key chains. You can also use zip ties or string to hold the cards together. Check out my other addition strategy units and games to go along with Race to Addition.