The objective is to model the use of equations to demonstrate the strategies of addition by place value, adding by keeping one number intact and adding the other in parts, and adjusting and compensating.
These are the basic strategies for addition. The premise to have students make sense of the numbers and value of the over all numbers and parts within each number. This is a departure from just teaching the traditional algorithm, where students essentially memorize the steps to carrying and where they often lose sight of the value of each digit within a number. The traditional algorithm is the last level taught to students only after they demonstrate mastery of what it represents.
There are three basic strategies for adding numbers together. There are different tools that can be used within each of these strategies; equations, unmarked number lines, stacking numbers, and lastly the traditional algorithm. The tutorials below model each of the strategies and and what it looks like using equations to work your way through to the final sum.
Source: Anne K. Flynn 2014