Add the fraction and denominator, the denominator remains the same, the numerator is added, and finally it becomes the simplest fraction.

Example:

2/9+5/9

=2+5/9

=7/9

Subtract the denominator fraction, the denominator remains the same, and the numerator is subtracted, which will eventually become the simplest fraction.

Example:

5/9- 1/9

=5- 1/9

=4/9

Steps to reduce:

1, numerator and denominator decomposition factor.

2. Find the common factor of numerator and denominator.

3. Exclude non-zero common factors.

If the greatest common divisor of numerator and denominator can be seen quickly, it is easier to divide by their greatest common divisor directly.