More about algorithms: Be sure to teach them in Guided Math Groups
Here is a variety of great resources that show different addition and subtraction algorithms.
Be sure to encourage math talk. It is not enough just to have students doing it different ways. They should be explaining their ways to each other. The first mathematical practice from the New Math Common Core states that:
Mathematically proficient students check their answers to problems using a different method, and they continually ask themselves, “Does this make sense?” They can understand the approaches of others to solving complex problems and identify correspondences between different approaches.
How are we making sure that this happens in our classroom? What kind of culture of “talk” are we fostering? What are we doing well and what can we do better?