Method 1 (Intuitive method):
The simplest method to know how 7/10 is greater than 1/2 is to familiarize yourself with the division operation. For example:
If we have the following rational number: 8/4, the division tells us how many 4s are needed to make 8. In this case, there are 2 fours needed to make 8.
Likewise:
7/10: There are 0.7 tens needed to make 7 as 0.7*10 = 7.
1/2: There are 0.5 twos needed to make 1 as 0.5*2 = 1.
It means that 0.7 > 0.5; therefore, 7/10 > 1/2.
Method 2:
1/2 can be represented as 5/10.
Now if we compare 5/10 with 7/10, we can see that 0.5 is less than 0.7. Hence 7/10 is greater than 1/2.