# Solving a fraction with shown work

I'm sitting here scratching my head and wondering what I'm missing. So here are is fraction like questions that I don't fully grasp. I gotten the answer with help of calculator a b/c function, but I would love if someone could break down the actual solution method.

18 feet - 9 inches 7/16 inch - 6 feet - 4 inches 15/16 inch

= 12 feet - 4 inches 1/2 inch

or

18' - 9 7/16" - 6' 4 15/16"

= 12' - 4 1/2"

Here I's what I can't quite understand. How does 9 7/16" - 4 15/16" becomes 4 1/2".

Because I can't minus 7 from 15 I would need to borrow a "1" from the 9. So we get 17. Now 17 - 15 = 2. So in theory it should be 2/16, now to bring that down we divide by 2 and the end result is 1/8.

Because we took a "1" from the 9 it's 8 - 4 = 4 so based on this the end solution must be

12 feet - 4 inches 1/8 inch

But this is not what I get if I use the a b/c function of my calculator. So what am I doing wrong or missing?

$9\ \frac{7}{16}-4\ \frac{15}{16}=8\ \frac{23}{16}-4\ \frac{15}{16}=4\ \frac{8}{16}=4\ \frac{1}{2}.$
What you did wrong is that when you carried the 1 over, you get $1+\frac{7}{16}=\frac{16+7}{16}=\frac{23}{16},$ not $\frac{17}{16}.$