One less than dominoes is also popular. Students work through the Elevens Alive lesson that is described in the Introduction to this Framework . It asks them to consider the parts of eleven and the natural, random, occurrence of different pairs of addends when tossing eleven two-colored counters. Second graders regularly use the doubles and near doubles , the make ten , and the counting on and counting back strategies for addition and subtraction. Practice sets of problems are structured so that use of all of these strategies is encouraged and the students are regularly asked to explain the procedures they are using.
Students play games like addition war to practice their basic facts.
Each of two children has half of a deck of playing cards with the face cards removed. Calculators may be used to check answers, if necessary. Any number can replace the 1 key. These situations encourage rapid recall of addition facts in a natural way. In order to extend practice to larger numbers, students may use 10-sided dice.