Describing a set of data by its mode (most common), median (middle value in order) and range (greatest minus least), from lists, line plots and stem-and-leaf plots.
Put the numbers in order first. The median is the middle one; with two in the middle, it's halfway between them. The mode appears most often. Range = greatest − least.
modethe value that appears most often
medianthe middle value once they're in order
rangegreatest minus least
stem-and-leaf plottens digits on the left, ones on the right
Watch for: Finding the middle of the list before putting it in order. Giving the greatest number as the range instead of greatest − least. Dropping repeated values when ordering, which moves the median.
At home: Collect a small set of data together, like minutes spent reading each day for a week, then find its mode, median and range.
Sample sheet and answer key
Luna's Space Adventure
Grade 4 · Mode, median and range · MA.4.DP.1.2
NameDate
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
Middle, most and spread
Put the numbers in order first. Range = greatest − least.
Data
Mode
Median
Range
39, 50, 50, 42, 42, 37, 42
29, 52, 40, 33, 40, 15, 47
36, 10, 10, 10, 36, 53, 22
Read the line plot
Each X is one measurement.
How many pencils?
Mode (most common)?
Median (middle value)?
Range (greatest − least)?
Stem-and-leaf plot
Minutes spent reading each day. The stem is the tens digit, the leaf the ones.
Stem
Leaves
5
0
6
0 1 2 5 5
7
1 3
8
2 5 8
5 | 0 means 50
How many numbers?
Mode?
Median?
Range?
Sheet
Luna's Space Adventure
Grade 4 · Mode, median and range · MA.4.DP.1.2
Answer key
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
Middle, most and spread
Put the numbers in order first. Range = greatest − least.
Data
Mode
Median
Range
39, 50, 50, 42, 42, 37, 42
42
42
13
29, 52, 40, 33, 40, 15, 47
40
40
37
36, 10, 10, 10, 36, 53, 22
10
22
43
Read the line plot
Each X is one measurement.
How many pencils?11
Mode (most common)?4 in
Median (middle value)?5 in
Range (greatest − least)?5 in
Stem-and-leaf plot
Minutes spent reading each day. The stem is the tens digit, the leaf the ones.
Stem
Leaves
5
0
6
0 1 2 5 5
7
1 3
8
2 5 8
5 | 0 means 50
How many numbers?11
Mode?65
Median?65
Range?38
Answer key
New problems every time, three levels (gentle, core and stretch), themes to pick from, a second page if you want one. Each sheet comes with an answer key and a one-page guide for grown-ups.
