4.MD.4: Line Plots with Fractions of a Unit
Also written as 4.MD.B.4 and CCSS.MATH.CONTENT.4.MD.B.4 · Cluster: Represent and interpret data.
The Official Wording
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Solve problems involving addition and subtraction of fractions by using information presented in line plots. For example, from a line plot find and interpret the difference in length between the longest and shortest specimens in an insect collection.
Common Core State Standards, Grade 4, Measurement & Data · Read it at the source · Checked October 14, 2026
What 4.MD.4 Means in Plain English
Fourth graders measure objects to the nearest 1/2, 1/4 or 1/8 inch, like a dozen pencil stubs, and mark one X per stub above a number line in that unit. Then they answer questions from the plot by adding and subtracting the fractions on it.
Halves and fourths must sit on an eighths scale, so students rename them with equivalent fractions (4.NF.1), then add and subtract like denominators (4.NF.3). In 5th grade, line plot problems share a total out equally (5.MD.2).
4.MD.4 I Can Statements
- I can measure lengths to the nearest 1/2, 1/4 or 1/8 inch.
- I can make a line plot with fractions on its scale.
- I can add and subtract fractions using data from a line plot.
4.MD.4 Worked Example
Ten bean sprouts measured in eighths, with a half and a three-quarter mixed in, so the scale has to be built before a single X goes up.
Ten bean sprouts were measured to the nearest 1/8 inch: 7/8, 1 3/8, 1 3/8, 1 1/2, 1 5/8, 1 5/8, 1 5/8, 1 3/4, 2 and 2 1/8 inches. Make a line plot. How much taller is the tallest sprout than the shortest? What do the 1 5/8-inch sprouts measure laid end to end?
- The list mixes halves, fourths and eighths. Rename them as eighths so every value has a mark on one scale.1 1/2 = 1 4/8, 1 3/4 = 1 6/8
- Draw a line from 7/8 to 2 1/8 with a mark at every eighth, including values nobody measured. Put one X above the mark for each sprout.Xs: 7/8 (1), 1 3/8 (2), 1 4/8 (1), 1 5/8 (3), 1 6/8 (1), 2 (1), 2 1/8 (1)
- Tallest minus shortest: read the two ends of the plot. There is only 1/8 to take 7/8 from, so trade one whole for 8/8.2 1/8 − 7/8 = 1 9/8 − 7/8 = 1 2/8 inches
- Three Xs stand above 1 5/8. Add the three lengths and turn the extra eighths into a whole.1 5/8 + 1 5/8 + 1 5/8 = 3 15/8 = 4 7/8 inches
Check it: Count up on the plot from 7/8 to 2 1/8: 10 jumps of 1/8, which is 10/8 = 1 2/8. And the Xs total 1 + 2 + 1 + 3 + 1 + 1 + 1 = 10, one per sprout.
Common Mistakes with 4.MD.4
Leaving halves and fourths off the eighths scale
1 1/2 and 1 3/4 plotted after 2 1/8, “because they aren’t eighths”
Try this: Rename every value into the plot’s unit before marking it: 1 1/2 is 1 4/8 and 1 3/4 is 1 6/8.
Reading the counts as the values
“Tallest minus shortest is 1 − 1 = 0,” because each end has one X
Try this: Point to the number under each X before writing anything. The values are on the scale, and the Xs only say how many.
Losing track of the data list
Nine Xs on the plot for ten sprouts, so every total built on it is off
Try this: Cross each measurement off the list as its X goes up, then check that the number of Xs matches the number of sprouts.
Where 4.MD.4 Fits
Practice 4.MD.4
Quick Check
- A line plot shows Xs at 1/8, 3/8, 3/8, 5/8 and 7/8 inch. How much longer is the longest object than the shortest?
- Four Xs sit above 1/4 mile on a line plot of walks. How far do those four walks total?
- Which marks does a line plot need to show 1/2, 3/4 and 5/8 inch on one scale?