Adding and Subtracting Common Denominators. To add or subtract any fractions, they must have the same denominator called a common denominator. Then, we simply add or subtract the numerators.
Use a number line to add and subtract. With multiplying and dividing just do it like a whole number. But remember, you take the sign of the larger number (example: -20 + 9 = -29). And when there is two negatives (interger)it equals a positive.I hope this helps!
