This is a test of commonsense. Complete the next sentence:

How to add mixed numbers
Add the whole numbers together.
The whole numbers are 1 and 2, so 1 + 2 =3.
Find the lowest common denominator (lcd) of both fractions.
The lcd is the lowest number that is evenly divisible by both numbers. Since the denominators of the fractions are 2 and 4, the lcd is 4, because 4 is the smallest number that is divisible by both 2 and 4.