Examine 2.5 miles first. One mile is equivalent to 5,280 feet, so multiply 2.5 by the conversion factor to get the equivalent in feet:

One foot is equal to 12 inches, so convert feet to inches by multiplying by 12:

One yard is equal to 3 feet, so convert feet to yards by dividing by 3:

2.5 miles, 13,200 feet, and 158,400 inches are all equivalent to one another, but 4,800 yards is not equivalent to any of these, since they are equivalent to 4,400 yards. 4,800 yards is the "odd man out".

Recall the relationship between cups and gallons. There are  cups in a gallon.

Thus, we can write the following to find out how many cups there are in  gallons.

There are exactly  in . So for every  we have  of that object.

We are given  of string, so in order to figure out how many  we have, we can divide our  by .

There are  's in , meaning that we have  in a .

Our answer is .

There are  in . So if we want to know how many  we have, we can simply multiply our number of , , by how many  are in a , .

There are  in .

Our answer is 

There are two ways you can solve this problem. 

First, know that every  makes up . So let's convert our  into  for now. To do this, we will take our  and divide it by  to get the correct amount of .

We now have . To get to , we must know that for every  we get . To convert our  to , we will divide our  by .

We now have  ,which is our answer. 

The second way to do this problem is if you know how many  are in a  and how many  are in a . Simply take how many  are in a  and how many  are in a  and multiply them together. Then, use that number to divide by .

Our answer is .

There are  in . In order to convert this to , we will need to divide our  by .

There is  in , so this is our answer.

Our answer is .

There are  in , so in order to solve this problem we must multiply  by  to convert this to .

 is equal to , so this is our answer.

Our answer is .

There are  in , and we are going from  from . So in order to convert , we will have to divide it by  to reach .

There are  in , so this is our answer.

Our answer is .

When converting  into , you must know that .

So we can see that we have , so we don't have enough to make . In order to convert this then, we must divide how much we have, , by how many  it would take to get a , which is .

So if we have , then in terms of  we have .

Our answer is .

Before we can pick up any bags, we need to know how many  the teacher is asking for first. The question states that Bob needs  for his bridge, so let's convert that to   by dividing it by . We do this because 

 comes out to , so we know how many  the teacher is asking for. Now let's look at our choices for bags.

 bag would be too little, as the teacher is asking for , and  or  bags would give us too many Popsicle sticks.

Since there is no bag that is , the bag we can get that is the closest to that number is . With  bags we will have enough Popsicle sticks in order to make the bridge, and it has the least amount of excess Popsicle sticks than   or .

Our answer is  bags.