# Lesson Video: Bar Graph With Scales of 2, 5, or 10 Mathematics

In this video, we will learn how to draw a bar graph with unit and nonunit scales and read bar graphs to solve one- and two-step comparison, sum, and difference problems.

10:04

### Video Transcript

Bar Graphs with Scales of Two, Five, or 10

In this video, we’re going to learn how to read or interpret information in bar graphs and use this information to help us answer questions.

This is a bar graph. The graph shows us the results of a shell hunt. Ben, Mia, and Sophie went on a shell hunt. The green bar shows us how many shells Ben collected. The orange bar shows us how many shells Mia collected. And the blue bar shows how many shells were collected by Sophie.

This is the scale. The scale tells us the number of shells collected by each person. The scale starts at zero and goes up in ones. One, two, three, four, five, six, seven, eight, nine, 10. This scale goes from zero to 10.

Let’s work out how many shells each person collected. This is the height of Ben’s bar. We need to draw a line across the top of Ben’s bar to the scale. Ben’s bar reaches the number five, which means that Ben collected five shells. This is Mia’s bar. Again, we’re going to draw a line across the top of her bar to the scale. Mia collected seven shells. Let’s do the same for Sophie’s bar. Sophie collected 10 shells.

In this video, we’re going to learn how to read scales of two, five, or 10. The scale in this bar graph goes up in ones. What if the scale went up in twos? The number of shells collected by each person would double. Ben collected 10. Mia would have collected 14 shells. And Sophie would have collected 20. When we’re reading information presented in bar graphs, we need to look very closely at the scale and work out what each mark or each interval is worth. Let’s try some practice questions. In these questions, we need to read scales of two, five, or 10.

The bar graph shows how many ice creams were sold at a fair. How many strawberry ice creams were sold? How many chocolate ice creams were sold?

The bar graph shows the flavors of ice cream sold at the fair. The different flavors were chocolate, and this is represented by the orange bar on the graph. The blue bar shows the number of vanilla ice cream sold. The green bar shows the number of mint ice cream sold. And the pink bar shows the number of strawberry ice cream sold. In the first part of the question, we need to work out how many strawberry ice creams were sold. And in the second part of the question, we need to work out how many chocolate ice creams were sold.

Let’s start with strawberry. Remember, that’s the pink bar. The numbers on the scale at the bottom tell us how many of each flavor of ice cream was sold. What does the scale go up by each time? Five, 10, 15, 20, 25, 30, 35, 40, 45, 50. This scale goes up in fives. Let’s count the number of strawberry ice cream sold. We need to count in fives. Five, 10, 15, 20, 25. 25 strawberry ice creams were sold. The pink bar reaches number 25 on the scale.

How many chocolate ice creams were sold? We need to look at the orange bar on the graph. And if we draw a line from the bar down to the scale, we can see that 40 chocolate ice creams were sold. The number of strawberry ice creams sold at the fair is 25, and the number of chocolate ice creams sold is 40.

The graph shows the number of boys and girls in two different classes. What is the largest number of boys in a class?

This bar on the graph shows us the number of boys in class two A. This bar shows us the number of girls in two A. This bar shows us the number of boys in two B. And this bar is the number of girls in two B. We have to find the largest number of boys in a class.

Which class has the most boys? Is it two A or two B? We can see that the number of boys in two A is more than the number of boys in two B. We can tell this because the bar for the two A boys is taller than the bar for the two B boys. How many boys are there in two A? We’ve drawn a line from the top of the bar, and we can see it’s between number 12 and 14. If the scale goes up in twos, then the number halfway between 12 and 14 is the number 13. The class with the largest number of boys is two A. There are 13 boys in this class, so the largest number of boys in a class is 13.

The bar graph shows how many children like each type of food for dinner. Which food is most popular? How many more children like pizza than curry?

This bar graph shows us children’s favorite dinners, burger, curry, or pizza. We have to read the information presented in the graph to work out which food is the most popular. To answer this question, we need to figure out which of the bars is the longest. It’s the pink bar. This means the food which is most popular is pizza.

In the second part of the question, we need to work out how many more children like pizza than curry. We can imagine the scale on the graph is a number line. And this is where the bar for pizza reaches on the number line, between the numbers 40 and 50. The difference between 40 and 50 is 10. And there are five small intervals. That means each of the smaller intervals is worth two. 40, 42, 44, 46, 48, 50. The number of children who like pizza is 42.

This arrow shows the number of children who liked curry the best. The number of children who like curry best is between the number 20 and 30 on the scale. And we know that each interval is worth two. So let’s start counting in twos from number 20. 20, 22, 24, 26. We have to find the difference between 26 and 42. We can start at number 26 on the number line and count forward in twos until we reach 42. Two, four, six, eight, 10, 12, 14, 16. 16 more children like pizza than curry. We read the information in the bar graph. The most popular food is pizza. We knew this because the pink bar is longest. 26 children preferred curry, and 42 preferred pizza. 16 more children like pizza than curry.

What have we learned in this video? We’ve learned how to read scales of two, five, or 10 on a bar graph.