# Question Video: Representing Telly Charts by Bar Graphs Mathematics • 2nd Grade

Daniel needed some school supplies. He used tally marks to record his requirements. Which of the following bar graphs represents the tally chart?

03:44

### Video Transcript

Daniel needed some school supplies. He used tally marks to record his requirements. Which of the following bar graphs represents the tally chart?

This problem tells us about someone who needs some supplies for school. And we’re told that he used tally marks to record what he wanted. And we’ve shown these tally marks in a tally chart. Do you remember how tally marks work? Each mark represents one more. And in this case, it’s one more object that Daniel needs. Instead of recalling them like this, where we have lots and lots of individual marks, it can be very difficult to count them; we’d be counting each one separately. Instead, what we do is as soon as we get to a multiple of five, one, two, three, four, and then the fifth one, we make into a block of five. So we have six, seven, eight, nine, 10. And so, by recording tally marks in blocks of five, it makes it much easier to count.

Let’s start then by counting how many of each type of supply Daniel needs. Firstly, the notebooks. We can see one group of five and then two more tally marks. And five plus two more is — seven. The next box we can see how many pens Daniel needs. And there are two groups of five tally marks, so that makes 10 pens. Next, we’ve got an eraser or a rubber. And we can see four individual tally marks, so that’s four erasers that he needs. And finally, on the end, we’ve got some backpacks. And we can see that he needs two backpacks, probably to told all this equipment in.

Next, we’re shown two bar graphs. And we’re asked which of the following bar graphs represents the tally chart. In other words, which one shows that Daniel is going to need seven notebooks, 10 pens, four erasers, and two backpacks? Let’s read them to find out. We’ll start by looking at the first bar graph. And we could look at the first bar on it, which we can see represents the number of notebooks that Daniel needs. If we put our finger on the very top of this bar and draw a line all the way across to the side, we can see that it reaches the number six. We can tell by the label that this represents the number of supplies Daniel needs. This bar graph tells us that Daniel needs six notebooks. But this is wrong, isn’t it? We know Daniel needs seven notebooks.

Let’s check the second bar graph and see if this is any better. And again, if we go to the top of the first bar and read across, this time we can see the correct answer. Daniel is going to need seven notepads. It looks like our second bar graph is correct, but let’s just read the other bars. They tell us that Daniel is going to need 10 pens, which is correct. He’s going to need four erasers, which is also correct. And if we look at the height of the final bar, we can see that he’s going to need two backpacks. Although the tally chart in the bar graph are two different sorts of things, they both show the same information and the bar graph that represents a tally chart is the one that shows that Daniel needs seven notebooks, 10 pens, four erasers, and two backpacks.