Yesterday annie walked 9tenth mile to her friends house they walk 1/3 mile to the library which is the best estimate for how far annie walked

This could be an adding fractions problem. We can add the two fractions together and then determine how many miles she walked.

 9       1
--- +
10     3

First, we need to find a common denominator. It would be 30, since this is the smallest number both 3 and 10 go into.

So, after that, we need to multiply each numerator by the number we needed to multiply our denominator by to get to 30.

So, 10 times 3 equals 30. So, we need to multiply 9 by 3 as well, which is 27.

Our new fraction here would be:

27

30

Next, to get 30, we need to multiply 3 by 10 to get 30. So, we also need to multiply 1 by 10, which is 10. 

Our new fraction would be:

10
---
30

So lets take a look at our new equation.

27   10
--- +  
30   30

Lets add them together. Remember the denominators need to stay the same:

37

30

Now that we have an improper fraction, we need to simplify it. 37 goes into 30 once, and we have 7 left over.

So, our final answer would be:

1 and 7
           of a mile.
          30