Number Line Comparison: Mapping Letters A-J to Integers from -4 to 5

Let's look at the number line and locate each letter:

$H=3$

$G=2$

$J=5$

$G-C=2-(-2)$

Let's now solve the problem whilst remembering the below rule:

$-(-x)=+x$

Therefore:

$G-C=2+2=4$

In conclusion J is the largest.