EngageNY 60 min(s)

In this lesson, students use linking cubes to add 9 and another single-digit number by decomposing the second addend to make ten with the 9. For example, they solve the problem "Maria has 9 snowballs, and Tony has 3. How many do they have altogether?" by making two groups (of 9 and 3), moving one cube over from the 3 to make a ten, and then adding 10 + 2 to find the solution.