Here are the answers:

1. To add/subtract fractions in a simple way, find first the LCD or the Least Common Denominator. Then divide the result to each of the denominators (in addends or the subtrahend and minuend), then multiply it upwards to numerator each. The result is to be put on the top of the LCD result. Then add/subtract them. Change it to mixed, or simplify if needed.

If it has the same denominator, just add/subtract the numerators, and copy the denominator. 

2. To multiply it, use cancellation if needed to the cross-fractions. Find their GCF, and do divide it to the current number. Then multiply the numerators and the denominators respectively.

3. To divide it, reverse the positions of the numbers in divisor, and do the multiplication method.