Calling it blocks is a little weird. but a good way to do it is to move left or right until you are over or below where you want to go then move up or down accordingly. Each move, left, right up or down will count as one block.
So from the fire station you go 1 to the right and then 6 down, for a total of 7. then from the library it's 3 right then 4 up, which is 7 again. 7 to the first stop then 7 to the second makes 14 total.
