🧱 See It
Imagine you plant a seed and measure how tall it grows every day. Each day you write down one number — its height in centimetres. Over five days, your measurements might look like this:
| Day | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Height (cm) | 2 | 5 | 9 | 10 | 10 |
Notice the plant grew a lot at first, then stopped growing between Day 4 and Day 5 — same height both days.
✏️ Draw It
A line graph plots one point per day, then connects the points with straight lines — so you can see the plant's height rising, then levelling off, in one continuous path:
The faint grid lines show every day (up-and-down lines) crossing every height (side-to-side lines). Each dot sits exactly where its day's line meets its height's line. The thicker line connecting the dots isn't new data — it's just showing the trend between the points you actually measured.
🔢 Write It
To read a value off a line graph, find the day on the bottom (horizontal) axis, trace straight up to the point, then trace straight across to the height (vertical) axis.
Reading the table above in words:
- From Day 1 to Day 3, the height is increasing — the line rises.
- From Day 4 to Day 5, the height stays the same — the line is flat (no growth).
💡 Worked Examples
Example — Which two days had the biggest jump in height?
Find the change from each day to the next by subtracting:
- Day 1 → Day 2:
5 − 2 = 3 - Day 2 → Day 3:
9 − 5 = 4 - Day 3 → Day 4:
10 − 9 = 1 - Day 4 → Day 5:
10 − 10 = 0
Compare the four changes: 3, 4, 1, 0. The largest is 4.
Answer: the biggest increase happened between Day 2 and Day 3.