Line Plots — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
A line plot in Grade 3 uses circles above each number to show data.
Corrected: A line plot in Grade 3 uses Xs above each number to show data.
Line plots in Grade 3 always use X marks, not circles, to record each piece of data above the matching number.
2. Fix the sentence:
Each X on a Grade 3 line plot stands for two data points.
Corrected: Each X on a Grade 3 line plot stands for one data point.
On a Grade 3 line plot, every single X represents exactly one data value, so counting Xs gives the count for that number.
3. Fix the sentence:
The numbers on a Grade 3 line plot scale go in random order.
Corrected: The numbers on a Grade 3 line plot scale go in order from least to greatest.
A line plot uses a number line, so the scale must be ordered from least to greatest with equal spacing between numbers.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. A line plot in Grade 3 shows data using X marks above each number on the scale.
Grade 3 line plots use X marks stacked above each number to make the count easy to see.
2. Each X on a Grade 3 line plot equals one data point.
Every X represents a single measurement, so the number of Xs equals the number of data points at that value.
3. The horizontal line at the bottom of a Grade 3 line plot is called the scale.
The scale is the number line that shows the possible values, and Xs are stacked above each scale number.
4. The value with the tallest stack of Xs is the most common value on a Grade 3 line plot.
The taller the column of Xs, the more often that value appeared, so the tallest stack is the most common value.
Part C: True or False?
Read each statement. Circle True or False.
1. On a Grade 3 line plot, you can put the same number of Xs above two different values.
True False
Two different scale numbers can each be measured the same number of times, so they can have equal stacks of Xs.
2. A line plot in Grade 3 must always start its scale at zero.
True False
A line plot scale only needs to cover the range of data, so it can start at any sensible number, not just zero.
3. A value with no Xs above it on a Grade 3 line plot was measured zero times.
True False
If a scale number has no Xs above it, no one in the data set had that measurement, so the count is zero.