Measuring to the nearest half and quarter inch
Generate measurement data by measuring lengths to the nearest half and quarter inch; display the data on a line plot with a scale marked in whole numbers, halves, and quarters
What a learner can do afterwards
- Measure five objects to the nearest 1/4 inch
- Create a line plot showing the lengths of classmates' pencils in half-inches
- Read a line plot and answer questions about the data
1 · Read
You already know how to measure things and build a line plot. Now you will measure closer: to the nearest half inch, or the nearest quarter inch. A ruler splits every inch into four equal quarter marks: 1/4, 1/2, 3/4, and the whole inch.
Five students measured their pencils to the nearest quarter inch: 2 in, 2 1/4 in, 2 1/2 in, 2 1/2 in, and 3 in. For each pencil, they put one X above its length on a number line marked in quarters.
Reading a line plot is counting. Each X stands for one object, so two objects with the same length get two X's stacked on that mark. The tallest stack is the most common length. To find how many more, count both stacks and subtract. Halves and quarters share one scale: 1/2 inch sits where 2/4 inch does.
Measure to the nearest quarter inch, mark an X for each length, and read the tallest stack to find the most common length.
2 · Watch
Take it off screen
Where it sits
Where this leads
8 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.