# Video: Reading Data from a Bar Graph Involving Subtraction

The graph shows the number of births at a hospital from 2003 to 2007. How many more births were there in 2007 than 2005?

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### Video Transcript

The graph shows the number of births at a hospital from two thousand and three to two thousand and seven. How many more births were there in two thousand and seven than in two thousand and five?

And we’ve been given a bar graph. Now a bar graph is a tool for showing and comparing frequencies of discrete data. Each bar represents a separate discrete piece of data, here the number of births in a particular hospital in a particular year. The height of the bar tells you about the frequency associated with each bar.

Now the fact that each bar represents a separate discrete piece of data means that the bars mustn’t touch each other. Okay let’s consider the question then. How many more births were there in two thousand and seven than in two thousand and five? So we’ve gotta use the bar graph to work out how many births there were in two thousand and seven and how many births there were in two thousand and five and then calculate the difference between the two.

So in two thousand and seven, there were, let’s just read this figure off from here, there were six hundred births. And in two thousand and five, the height of that bar is four hundred births.

Now the difference between six hundred and four hundred: six hundred take away four hundred is two hundred. There were two hundred more births in two thousand and seven than there were in two thousand and five. This bar here, the two thousand and seven, is higher than this bar here for two thousand and five, and the difference between the two is two hundred births.