Bigger bar charts and rounding · Usually met around P4
Starting line graphs
Read the scale's step first; steeper means a bigger change.
How to do it
Method
Read the scale's step first; steeper means a bigger change
18°C up to 24°C: 24 − 18 = 6
Another way
Count the steps
3 steps up at 2°C: 3 × 2 = 6
In full
A line graph uses points and lines to show how something changes over time, such as the temperature through a day. First read the scale: where it starts and how much each step is (it needn't start at 0, and a step needn't be 1). To read a value, find the time along the bottom, go up to the point, then across to the scale. The highest point is the highest value, the lowest point the lowest. A line going up is a rise, going down a fall, and flat means no change; the steeper the line, the bigger the change. To find a change, take the earlier point from the later: 24 − 18 = 6, a rise of 6°C. Another way: count the steps, 3 steps up at 2°C each, 3 × 2 = 6.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
The line graph shows the temperature (°C) at different times of one day. What was the highest temperature that day, in °C?
Show the answer and working
Answer: 24°C
The highest point lines up with 24 on the scale: 24°C.
Example 2
The line graph shows the temperature (°C) at different times of one day. The highest was □°C, the lowest □°C, a difference of □°C.
Fill in each box
Show the answer and working
Answer: 30，16，14
The highest point is at 30 and the lowest at 16: 30 − 16 = 14.
Example 3
The line graph shows the temperature (°C) at different times of one day. In which stretch of time did the temperature rise the most?
- A. 14:00 to 17:00
- B. 08:00 to 11:00
- C. 11:00 to 14:00
- D. 17:00 to 20:00
Choose the right answer
Show the answer and working
Answer: C. 11:00 to 14:00
A line going up means a rise, and the steeper, the bigger: take each stretch's difference; the most is 4°C.
Practise it in the game →Bigger bar charts and rounding · Free to start, unlimited questions, no download