Ask family to quiz you on your multiplication tables. Once you have studied them enough to know them well, ask your family to quiz you on the tables you have just learned. This will help you remember them long term and keep the numbers fresh in your head. When you have all the tables memorized, ask them to quiz you on all of the numbers, not just one number at a time.
If the two values being subtracted are mixed fractions, it is often easier to turn them into improper fractions to perform the subtraction. This avoids any kind regrouping or borrowing from the minuend fraction if the numerator in the subtrahend is larger.