Line plots with fractions of a unit
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8); use operations on fractions to solve problems involving data in line plots (e.g. redistribute total equally)
What a learner can do afterwards
- Create a line plot showing lengths measured to the nearest 1/8 inch
- Use the line plot to find the total of all measurements by adding fractions
- Solve: 'If the total liquid were redistributed equally among all beakers, how much would each have?'
1 · Read
You already know how to read a line plot and add fractions with different denominators. Each X stands for one measurement. Stack Xs above the same length when measurements repeat. A line plot can show pencil lengths in fractions of an inch. Add every pencil's length to find the total. Divide that total equally to find each person's share.
To find the total length of all the pencils, add each length once for every pencil at that mark: 1/4 + 1/4 + 3/8 + 1/2 + 1/2 + 1/2 + 5/8 + 5/8. Rewrite everything in eighths first, then add. The total comes out to 3 5/8 inches.
When you add fractions from a line plot, find a common denominator first. If every mark on the plot is already in eighths, that part is done for you.
A line plot can also help you share a total fairly. Four beakers hold 1/2, 1/2, 1/4, and 1/4 cup of water. Poured together, that is 1 1/2 cups. Split evenly among the 4 beakers, each one gets 3/8 cup.
Read how many Xs sit above each value. Add one length per X for the total, then divide to share it equally.
More to read
Basic Line Plots
A line plot is a number line with an X for every measurement. Each X stands for one thing you measured, like one bean or one nail. You read the plot by counting how many X marks sit above each value. The tallest stack shows the most common measurement. Line plots turn a messy list of numbers into a picture you can read at a glance.
Practice with Line Plots
Fractions show up on line plots when you measure to the nearest half, quarter or eighth of a unit. To find a total, add up every value that has an X above it. If three X marks sit above 1/2, that group contributes three halves. Convert the fractions to a shared denominator first, then add. Sharing a total equally means dividing it by the number of X marks.
Line plots review
Start every line plot with a labelled number line that covers all your data. Place one X above the line for each measurement, stacking them neatly. Check that your count of X marks matches your count of measurements. Then the plot is ready to answer questions. Totals come from adding, and fair shares come from dividing the total by the number of marks.
Represent data on a line plot
Scientists plot repeat measurements to see how much the readings vary. A cluster shows the values measured most often, not proof of the true value. A ruler placed off zero can shift every reading. Add the readings and divide by their count to find the average. Check the measuring tool and method too; repeating a shifted reading does not fix it.
Explore more
2 · Watch
En anglaisTake it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
18 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.