3
Bars and class data
Discover Term 1: Axis 1, Chapter 3
GoalRead a bar graph and find the most and the least.
New words
bar graph · a graph that uses barsdata · facts we collect, like answers we countleast · the smallest number
Explanation
A bar graph uses bars instead of pictures. The taller the bar, the more there is. We can ask our class a question and collect data. Then we count the answers and draw one bar for each kind. This graph shows favourite colours: red 5, blue 6, green 3 and yellow 4. Blue is the most. Green is the least.
Worked examples
Hair in our class: short 6, medium 4, long 3. Most children have short hair. Fewest have long hair.
Look at the bars for red (5) and blue (6). Blue is 1 more than red.
Our graph needs a question, answers we count, and a bar for each answer.
Class activity
Class data. Ask 10 people which colour they like best: red, blue, green or yellow. Make four towers of small squares (or draw bars) on squared paper, one for each colour. Which colour is the most? Which is the least?
Practice
1
Which bar is the tallest, and what does it show?
Football. It is the favourite game of the most children.
2
In the graph above, how many children like kites?
3
3
Which game has the least children?
Kites.
4
In a bar graph, what does a taller bar mean?
There is more of that kind.