The following image was made by Add Fractions Designer :

Addition with Fractions - Strict is similar to the previous program ADD UNLIKE FRACTIONS except that the addends may be mixed numbers and the sum must be entered so that the numerator is smaller than the denominator and the numerator and denominator are in lowest terms.

See the program MIXED NUMBERS for information on writing fractions in mixed form.

See the program RENAME IN LOWEST TERMS for information on writing fractions in lowest terms.

The above illustration shows that the addends are written with a common denominator 12. The numerators 8 and 9 are then added for a numerator of 17 in the sum. The sum 3 17/12 can be simplified because the 17/12 is equal to 1 5/12 in mixed form. The 1 in 1 5/12 is added to 3 for a simplified sum of 4 5/12 The sum must be entered in in lowest terms. So in the above example, only 4 5/12 is acceptable.

Another method is to work vertically as shown below:

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