Line plots are number lines that that show the frequency of each value in a set of data. Line plots help you record data in a very well organized way. The data is usually recorded with a "X."
For example, you are making a line plot of how many slides there are in parks. Let's say the data set is 5, 6, 8, 9, 10, and 11. The first step you would do would be putting your numbers in order from least to greatest. Second you will draw a line with a arrow on the ends. Third you will make a mark on the line for each number between 5 and 11. Remember you still need to put a mark on the line for 7, even though it's not one of the numbers we're dealing with, it's still between 5 and 11. Next you will put an "X" above the line each time that number occurs in the data set. Then… poof! You have a line plot.