Final answer:
To compare 7/8 and 2/4, simplify 2/4 to 1/2. Then, find a common denominator to see that 7/8 is greater than 1/2 (or 4/8), so 'is greater than' is the phrase that completes the comparison.
Step-by-step explanation:
To compare the two fractions 7/8 and 2/4, we need to look at their values. The fraction 2/4 can be simplified to 1/2, as the numerator and denominator can be divided by 2, which is an equivalent fraction. Now, we compare 7/8 and 1/2. Since 1/2 is equal to 4/8 when we find a common denominator, we can see that 7/8 is greater than 1/2 (or 4/8). Therefore, the phrase that should be inserted on the line to completely compare the two fractions is 'is greater than' (7/8 is greater than 2/4).