All of the questions follow the same procedure, so I'll give you the answer just for the first question shown, question 3. Firstly, what is a unit rate? A unit rate is a rate for one of something. An example of a unit rate is "5 miles per hour", where "5 miles" is the rate, and "hour" is the something.
Number three: 8 pencils for 10 dollars. The question is asking: "How many pencils do you get for one dollar?". We can find this through division:
> (8 pencils) / (10 dollars)
> 8/10 pencils per dollar
> 4/5 pencils per dollar
The final number in decimal form, 0.8 pencils per dollar, is the answer to number 3.
Now try number 4. The correct answer for number 4 is about 1.55 batteries per dollar. Did you get this same answer? If not, comment on my answer, and I may be able to try and help you through another problem.
