Year 5: Reading a line graph
Part of the Year 5 statistics chapter. Chapter overview · whole chapter on one page
Reading a line graph
A line graph shows how something changes over time. A point is marked for each time or week, and a line joins the points. You can see at a glance whether the value goes up, goes down or stays the same.
Before you read any value, look at three things: the title, the axis along the bottom (the time, the week or the day) and the scale up the side (the value, with its units).
To read a value: find the time or week along the bottom, go up to the line, then go across to the scale.
Key ideas
- Read the title, the axis and the scale before you read any value.
- To read a value: go along the bottom, up to the line, then across to the scale.
- To find the time for a value: start on the scale and work back to the bottom.
- A line that goes up means the value is increasing. A flat line means no change.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 12:00 along the bottom of the graph. The bottom of the graph shows the time.12:00
- Go up from 12:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 12 °C
- Write the answer. 12 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Start at the value on the scale, go across to the line, then down to the time or week.
- Find 14 °C on the scale. The scale on the side tells you the height of each gridline.14 °C
- Go across to the Temperature line. Find the point at that height on the line.across to the point
- Go down to the bottom of the graph. The time or week under the point is the answer.down to 13:00
- Write the answer. 13:00
Check. Read 13:00 again and the value there is 14 °C. ✓
Watch out. Start from the scale, not from the bottom of the graph.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 3 along the bottom of the graph. The bottom of the graph shows the week.Week 3
- Go up from Week 3 to the Leo's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 14 cm
- Write the answer. 14 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Watch out
Watch out: read the value at a point. The line between two points shows the change, but it does not give an exact value for a time between them. Also count the gridlines, because a label may be shown only on every second gridline.
Exercise 11A Reading values from a line graph
Non-calculatorKey words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 11:00 along the bottom of the graph. The bottom of the graph shows the time.11:00
- Go up from 11:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 10 °C
- Write the answer. 10 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 09:00 along the bottom of the graph. The bottom of the graph shows the time.09:00
- Go up from 09:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 6 °C
- Write the answer. 6 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 15:00 along the bottom of the graph. The bottom of the graph shows the time.15:00
- Go up from 15:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 10 °C
- Write the answer. 10 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Look for the highest point, then read along to the bottom.
- Find the highest point on the line. That point has the greatest value on the scale.highest point = 14 °C
- Go down from that point to the bottom of the graph. The time or week under the point is the answer.down to 13:00
- Write the answer. 13:00
Check. Every other point is lower than 14 °C. ✓
Watch out. Look at the height of the point, not the last point on the graph.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Start at the value on the scale, go across to the line, then down to the time or week.
- Find 12 °C on the scale. The scale on the side tells you the height of each gridline.12 °C
- Go across to the Temperature line. Find the point at that height on the line.across to the point
- Go down to the bottom of the graph. The time or week under the point is the answer.down to 12:00
- Write the answer. 12:00
Check. Read 12:00 again and the value there is 12 °C. ✓
Watch out. Start from the scale, not from the bottom of the graph.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 4 along the bottom of the graph. The bottom of the graph shows the week.Week 4
- Go up from Week 4 to the Aisha's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 18 cm
- Write the answer. 18 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 6 along the bottom of the graph. The bottom of the graph shows the week.Week 6
- Go up from Week 6 to the Leo's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 24 cm
- Write the answer. 24 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Start at the value on the scale, go across to the line, then down to the time or week.
- Find 14 cm on the scale. The scale on the side tells you the height of each gridline.14 cm
- Go across to the Leo's plant line. Find the point at that height on the line.across to the point
- Go down to the bottom of the graph. The time or week under the point is the answer.down to Week 3
- Write the answer. Week 3
Check. Read Week 3 again and the value there is 14 cm. ✓
Watch out. Start from the scale, not from the bottom of the graph.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Thursday along the bottom of the graph. The bottom of the graph shows the day.Thursday
- Go up from Thursday to the Steps line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 9,000 steps
- Write the answer. 9,000 steps
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 1,000 steps, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Look for the lowest point, then read along to the bottom.
- Find the lowest point on the line. That point has the smallest value on the scale.lowest point = 5,000 steps
- Go down from that point to the bottom of the graph. The time or week under the point is the answer.down to Wednesday
- Write the answer. Wednesday
Check. Every other point is higher than 5,000 steps. ✓
Watch out. Look at the height of the point, not the last point on the graph.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 10:00 along the bottom of the graph. The bottom of the graph shows the time.10:00
- Go up from 10:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 8 °C
- Write the answer. 8 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 13:00 along the bottom of the graph. The bottom of the graph shows the time.13:00
- Go up from 13:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 14 °C
- Write the answer. 14 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find 15:00 along the bottom of the graph. The bottom of the graph shows the time.15:00
- Go up from 15:00 to the Temperature line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 10 °C
- Write the answer. 10 °C
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 °C, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 2 along the bottom of the graph. The bottom of the graph shows the week.Week 2
- Go up from Week 2 to the Aisha's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 8 cm
- Write the answer. 8 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 2 along the bottom of the graph. The bottom of the graph shows the week.Week 2
- Go up from Week 2 to the Leo's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 6 cm
- Write the answer. 6 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Key words. A line graph joins points with lines. The scale up the side shows the value of each gridline. The axis along the bottom shows the time, the week or the day.
Method. Find the time or week, go up to the line, then across to the scale.
- Find Week 5 along the bottom of the graph. The bottom of the graph shows the week.Week 5
- Go up from Week 5 to the Leo's plant line. The point on the line shows the value at that time or week.up to the point
- Go across to the scale on the side. The scale tells you how big the value is.reads 16 cm
- Write the answer. 16 cm
Check. The point sits on a gridline, so the reading is exact. ✓
Watch out. Each gridline is worth 2 cm, so count the gridlines carefully.
Method. Find the two plants in Week 3 and Week 4, then compare the heights.
- Read Aisha's plant in Week 4. Go up from Week 4 to the top line of the plant graph.18 cm
- Read Leo's plant in Week 4. Do the same for Leo's plant.16 cm
- Compare the two heights. The taller plant has the bigger height.18 cm is more than 16 cm, so Aisha's plant is taller
- Write the answer. No, Sam is not right. In Week 4 Aisha's plant was taller.
Check. 16 cm + 2 cm = 18 cm, so Aisha's plant was 2 cm taller. ✓
Watch out. Read both lines in the same week before you say which plant is taller.
Method. Read the steps for each day in order, then check whether each day goes up from the day before.
- Read the steps for Monday to Wednesday. Go up from each day to the line.Monday 6,000, Tuesday 8,000, Wednesday 5,000
- Compare Tuesday with Wednesday. A line that goes down shows a fall.8,000 is more than 5,000, so the steps fell
- Decide. The steps did not go up every day, so the statement is not true.No
Check. Monday to Tuesday goes up, but Tuesday to Wednesday goes down. ✓
Watch out. A line that goes up and then down is not steadily rising. Check every pair of days.