Making Line Plots of Lengths
A 45-minute Grade 2 lesson on measuring several objects to the nearest inch and showing the lengths on a line plot, where the scale has to include the lengths nobody measured.
Making Line Plots of Lengths is a free 45-minute Grade 2 math lesson plan for Common Core standard 2.MD.D.9 — measure several objects and show the lengths on a line plot. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 2
- Length:
- 45 minutes
- Standard:
- 2.MD.D.9
Grade 2 · Measurement & Data
2.MD.D.9
Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.
Objective
Students will be able to measure several objects to the nearest whole inch, show the measurements on a line plot, and answer questions from it.
Students are successful when they can
- Draws a scale marked in equal whole-inch steps that covers every measurement.
- Places one X above the right number for each measurement.
- Answers 'how many' and 'how much longer' questions from the plot.
What you need
- Inch rulers
- A tub of crayons or pencils of different lengths, enough for each pair to measure ten
- Chart paper with a blank horizontal line
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — measure one
5 min- Measure one pencil to the nearest inch with the class, lined up at 0.
- Ask what to do when the end falls between 5 and 6. Choose the nearer whole inch, and say that is what 'to the nearest inch' means.
Teach — one X for each length
13 min- Put up ten pencil lengths the class measured: 5, 6, 6, 7, 4, 6, 5, 7, 6 and 8 inches.
- Ask how to see which length is most common. A list does not show it at a glance.
- Draw a line and mark it 4, 5, 6, 7, 8 with equal spaces. Say the scale is a piece of ruler: same steps, in order.
- Place an X above the number for each pencil, crossing each length off the list as it goes on. Stack repeats one above another.
- Count the X's: 1, 2, 4, 2 and 1 make 10, one for each pencil. Ask which length is most common — 6 inches.
- Ask how much longer the longest pencil is than the shortest. Read it from the scale: 8 − 4 = 4 inches.
“Each X is one thing we measured. The number under it is how long that thing is. The scale counts by ones and does not skip a number, even when nothing is that long.”
Guided practice — measure and plot
12 min- Pairs measure ten crayons to the nearest inch and list the lengths.
- They draw a scale from the shortest to the longest length and plot one X per crayon.
- They check that the number of X's equals the number of crayons, then write one 'how many' and one 'how much longer' question for another pair.
Independent practice
12 min- Students complete a line plot page.
- Look at the scales before the X's. A scale that jumps from 6 to 8 because nothing measured 7 is the most common error and changes how every answer reads.
Close
3 min- Show a finished plot with no X above 7 and ask why 7 is on the scale at all.
- Because the scale is a ruler. An empty spot is information: no pencil was 7 inches long.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Leaves out a number on the scale because nothing measured that length.
Why: The scale is being built as a list of the answers rather than as a measuring line, so a length with no X seems to have no reason to be there.
Fix: Lay a ruler along the scale while drawing it. Every inch on the ruler gets a mark on the line, whether or not an X will go above it.
Reads the number of X's above a length as the length itself.
Why: Most graphs met so far showed counts, so the tallest stack seems to be the biggest answer to every question.
Fix: Point to one X and ask what it stands for: one pencil. Then ask how long that pencil is. The number below answers the length; the stack answers how many.
Places X's with uneven spacing, so a stack of three looks shorter than a stack of two.
Why: The X's are being drawn as marks rather than counted as units, so their size and spacing have not seemed to matter.
Fix: Plot on grid paper with one square for each X. Equal squares make the stacks comparable, the same way equal spaces make the scale readable.
If they are not there yet
- Give a scale already drawn and labeled, so the task is placing X's and counting them.
- Plot with sticky notes first, one per object, before drawing X's.
If they finish early
- Measure the same object five times, plot the repeated measurements, and explain why they are not all the same.
- Write a question that the line plot cannot answer, and say why.
- Make a line plot from a set of lengths that has a gap of two inches in the middle, and explain the gap.
Exit ticket
Five crayons measure 3, 4, 4, 4 and 6 inches. Make a line plot. How many crayons are 4 inches long? How much longer is the longest than the shortest?
What to look for: A scale of 3, 4, 5, 6 with 5 included, three X's above 4, and 6 − 3 = 3 inches. A scale with no 5 means it was built from the data list; an answer of 4 to the second question means the marks from 3 to 6 were counted instead of the spaces between them.
Printable practice for 2.MD.D.9
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Make a Line Plot — Whole InchesDraw the line plot.
Questions about Making Line Plots of Lengths
How long does the Making Line Plots of Lengths lesson take?
45 minutes, split across 5 timed sections: warm-up 5 min, teach 13 min, guided practice 12 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Making Line Plots of Lengths teach?
CCSS.MATH.CONTENT.2.MD.D.9 — 2.MD.D.9, Measurement & Data for Grade 2: “Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.” In plain terms, measure several objects and show the lengths on a line plot.
What do I need to teach this lesson?
Inch rulers, a tub of crayons or pencils of different lengths, enough for each pair to measure ten, chart paper with a blank horizontal line and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: leaves out a number on the scale because nothing measured that length; reads the number of X's above a length as the length itself and places X's with uneven spacing, so a stack of three looks shorter than a stack of two. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “Five crayons measure 3, 4, 4, 4 and 6 inches. Make a line plot. How many crayons are 4 inches long? How much longer is the longest than the shortest?.” A scale of 3, 4, 5, 6 with 5 included, three X's above 4, and 6 − 3 = 3 inches. A scale with no 5 means it was built from the data list; an answer of 4 to the second question means the marks from 3 to 6 were counted instead of the spaces between them. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Making Line Plots of Lengths?
Yes — 1 printable 2.MD.D.9 worksheet, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Making Line Plots of Lengths free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on October 22, 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-10-22. Aligned to 2.MD.D.9 of the Common Core State Standards for Mathematics.