You have made line plots of whole-inch lengths. Now that you can measure to the nearest quarter inch, the line plot needs halves and quarters on its scale.
Why it works
A line plot is a number line with an X above the spot for each measurement. Measurements that are the same stack up, so you can see at a glance which lengths are common, which are rare, and how spread out they are. The scale must match the measurements: quarter-inch data needs quarter marks.
Key idea
Draw a number line marked in the same units as the data (halves or quarters). Put one X above the matching mark for each measurement. Then count Xs to answer questions.
Worked example: Make the plot
Leaf lengths: $\frac{1}{2}$, $\frac{3}{4}$, $\frac{3}{4}$, 1, 1, 1, $1\frac{1}{4}$, $1\frac{1}{4}$, $1\frac{1}{2}$, $1\frac{3}{4}$ inches. How do you plot them?
- Mark a line from 0 to 2 in quarter inches.
- Put one X for each leaf: 1 at $\frac{1}{2}$, 2 at $\frac{3}{4}$, 3 at 1, 2 at $1\frac{1}{4}$, 1 at $1\frac{1}{2}$, 1 at $1\frac{3}{4}$.
- Check: $1 + 2 + 3 + 2 + 1 + 1 = 10$ Xs for 10 leaves.
Answer: the plot above
Worked example: Read the plot
How many leaves are longer than 1 inch?
- Look to the right of 1, not at 1.
- $2 + 1 + 1 = 4$.
Answer: 4 leaves
Common mistake
Putting an X at the wrong mark. On a quarter-inch scale, $\frac{1}{2}$ is the second small mark, the same as $\frac{2}{4}$. Count quarters from the whole number before it. And make sure the number of Xs matches the number of measurements.