Interpreting bar graphs: colors

CCSS Math: 3.MD.B.3

Video transcript

- [Voiceover] Chelsea asked 600 people at her school their favorite color and graphed the results. Some colors are not on Chelsea's graph. How many people chose colors other than those on Chelsea's graph? So, here's Chelsea's graph, she made a bar graph, and she listed some favorite colors, blue, green, red, yellow, pink, and graphed people who had those favorite colors. But, some of these 600 people, like me, had a different favorite color. My favorite color, orange, isn't on the graph. So, we're asked how many people like me were not graphed. How many people picked a different color besides blue, green, red, yellow, and pink? So, the way we can figure this out is if we look at the graph and find out how many of the 600 people are on the graph, then we can take that away from the total 600 people to find out how many are not on the graph. So, we'll start by looking at the graph. First one, blue, this bar lines up to 90. So, 90 people picked blue. Plus, next one, green, lines up to 135, 135 people picked green. Moving over to red, this bar lines up to 75, 75 more picked red. Yellow and pink, the bars are the same heights, that means the same amount of people picked yellow and red, and we can move over and see that that was 120, so 120 picked yellow, and another 120 picked red. So, if we combine all of these numbers, combine all of the people that are on the graph, that will help us to figure out how many are not on the graph. So, let's start, let's start with the ones. Zero ones, plus five ones is five ones, plus five more ones is 10, plus zero is still 10, plus zero is still 10, so we have 10 ones, plus, let's look at our tens, nine tens plus three tens is 12 tens, 12 tens plus seven tens is 19 tens, 19 tens plus two is 21 tens, and two more tens 21 tens plus two more tens is 23 tens, so we have 230 tens, or 230, that zero because we're talking about tens, plus, we can now do our hundreds, only a few of these had hundreds, we had one hundred, plus another one hundred is two hundreds, plus another is three hundreds, so three hundreds, we have two zeros now because we're talking about hundreds, three hundreds. And, if we add all of these, 10 plus 230, 230 is 240, and 240 plus 300, well, let's see, that will still be 40 but 200 plus another 300 is 500. So, 540 people are on the graph, but we're asked how many are not on the graph. So, up here, we see there are 600 total people were asked, 600 total people, and we want to take away the 540 who were on the graph, and that will tell us how many were not on the graph. If we take these people away, everybody who's left is like me, who's favorite color is not on the graph. So, let's do that. If we started with 600 and we're subtracting 540, let's first subtract the 500. 600 minus 500 is 100. But we still need to subtract the 40. 100 is like 10 tens, minus 40 which is four tens, 10 tens minus four tens is six tens, or 60. So, there were 60 people who chose colors other than those on Chelsea's graph.