The following picture was made by Addition With Lines Designer:

The parts of an addition example are the first addend, the second addend, and the sum.

When the program starts, you will be asked to identify the first addend and then the second addend. The program will not continue unless each addend is correctly identified. You will then be asked to add each addend for the sum.

You can see from the picture that the first addend is 2 2/11 units in length and the second addend is 1 2/11 units in length. The sum will combine these two lengths for 3 4/11 units.

To calculate the Sum first add the whole numbers 2 and 1 to obtain 3 for a whole number. Then add the numerators of the fractions 2/11 and 2/11 to obtain the 4/11 in the sum.

You may prefer to work vertically:

or you may prefer to write each addend in fraction form first:

In many examples, the sum may be found by visually combining the two addends.

You may enter the sum in fraction form or mixed number form. In the above example 37/11 or 3 4/11 are both acceptable.