GoalMeasure a standing jump in centimetres, record it in a tally chart and show it in a bar graph.
New words
tally chart · a chart where we draw one mark for each answerrange · a group of numbers between two limits, such as 100 to 119bar graph · a graph that uses bars to show how manydata · facts and numbers we collect
Explanation
In a standing jump you stand with both feet behind a line, swing your arms and leap ahead, trying to land as far from the line as you safely can. A grown-up marks where your heels land and measures from the line in centimetres. Jump on a flat floor that is not slippery. When many children jump, we collect data. A tally chart helps us count: we draw one mark for each child, and the fifth mark crosses the four before it. Because jumps are all different, we put them into ranges, for example 100–119 cm. Then we can show the data in a bar graph. The longest bar shows the range with the most children. The shortest bar shows the range with the fewest. A good graph also needs a title and labels, so the reader knows what the bars show.
Way to show data
Good for
Tally chart
Counting answers while I ask
Table of numbers
Exact numbers
Bar graph
Seeing the most and the fewest at once
Worked examples
Habiba jumps from the line. Her grown-up measures from the line to her heels and finds 112 cm. Habiba writes 112 cm. It belongs in the range 100–119.
A class asks 15 children to jump. The tally chart shows 1 + 3 + 5 + 4 + 2 = 15 children, so every child is counted once.
The same data in a bar graph. The tallest bar is 100–119 cm with 5 children. The shortest bar is “less than 80” with 1 child.
Class activity
Jump day. With a grown-up, mark a line with tape on a flat, dry floor. Each child jumps twice and the grown-up measures the better jump. Write each distance in cm. Then make a tally chart with the ranges: less than 80, 80–99, 100–119, 120–139, 140 or more. Draw the bar graph. Which range has the most children?
Practice
1
How many children jumped 100–119 cm?
4
2
In the graph, which range has the fewest children?
140 or more (1 child).
3
Salma jumped 118 cm. In which range does her jump belong?
100–119.
4
Name two things a good graph needs so that the reader understands it.
