CIE IGCSE Maths - Core - Statistical Diagrams - Stem & Leaf Diagrams - How to draw and find the median

Oct 26, 2026

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Revision notes for CIE IGCSE Maths Core on statistical diagrams, focused on stem-and-leaf diagrams and frequency table basics. The material defines what a stem-and-leaf diagram is, explains how to split two-digit data into stems (tens) and leaves (units), and guides learners through drawing a rough diagram, ordering stems and leaves, and adding a key. It also shows a worked example using blood pressure reduction data and demonstrates how to determine the median from the diagram. It then introduces tally charts and frequency tables.

LanguageEnglish

CategoryExam

FormatPDF

Pages27

Reading Time1 h 8 min

AccessFree to download

Statistical Diagrams

Stem & Leaf Diagrams

How do I draw a stem-and-leaf diagram?

How do I find the median from a stem-and-leaf diagram?

Worked example

Tally Charts & Frequency Tables

What is a frequency table?

What is a tally chart?

Head to www.savemyexams. com for more awesome resources CIE IGCSE Maths: Core Statistical Diagrams Contents Stem & Leaf Diagrams Tally Charts & Frequency Tables Bar Charts & Pictograms Pie Charts Histograms & Frequency Polygons Working with Statistical Diagrams Page 1 of 27 © 2015 − 2024 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Your notes Head to www.savemyexams. com for more awesome resources Stem & Leaf Diagrams Stem & Leaf Diagrams Whatisa stem-and-leaf diagram? A stem-and-leaf diagram is a simple but eyective way of showing data the raw data is still available asthe numbers themselves create the diagram A stem-and-leaf diagram puts data into order puts data into classes (groups) A stem-and-leaf diagram makes patterns in the data easy to see as the data is in order it is useful for |nding the median Stem-and-leaf diagrams are particularly useful for two-digit data but can be used for bigger numbers two-digit data could be something like 26 but could also be 2 .6 due to this, it is essential a stem-and-leaf diagram has a key How doI draw a stem-and-leaf diagram? The digits from each value in the data are split into two – stems and leaves e. g. the data value 26 would be split into a stem of 2 and a leaf of 6 As in nature though, a stem can have more than one leaf, so the stems become our classes in our data e. g. the stem of 2 becomes a class interval – covering values from 20 to 29 Any other values in the 20’s would join the same stem/class – so astem of 2 could end up having two or more leaves To draw a stem-and-leaf diagram . . . STEP 1 Page 2 of 27 © 2015 − 2024 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Your notes Head to www.savemyexams. com for more awesome resources Unless the data is in order, always draw a rough stem-and-leaf diagram |rst Work through the data one value at a time, splitting each into a stem and a leaf Lightly cross each data value out as you use it-this will help to ensure none are missed out This gets the data into the right format, grouped into its stems, with the correct number of leaves STEP 2 Draw a |nal diagram with the stems in (ascending) order For each stem, rearrange the leaves into (ascending) order Ensure your leaves are lined up in neat columns (so the size of each stem/class can be easily seen) STEP 3 Add a key to your diagram to explain how the two digits have been split into stems and leaves e. g. does 2|6 mean 26 or 2 . 6? The key will let us know! How doI |nd the median from a stem-and-leaf diagram? To |nd the median ... Lightly cross out numbers from the beginning and end i. e. -cross out the lowest number and the highest number be careful with the highest number- it will be at the end of the last stem Continue crossing out the next lowest/highest numbers until you meet in the middle if two numbers remain in the middle, |nd the midpoint between them if the midpoint isn 't obvious then add them together and halve A common mistake when |nding the median isto not put the number back into its original format and to only use the leaf e. g. Median = 6 instead of Median = 26 Page 3 of 27 © 2015 − 2024 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Your notes Head to www.savemyexams. com for more awesome resources | Worked example
A hospital is investigating a new drug that claims to reduce blood pressure. They give a set of patients the new drug and three hours later record the amount the blood pressure of every patient has reduced (or increased) by. The results, measured in mmHG (millimetres of mercury) are given below.
12 31 24 18 21 34 40 19 23 17 16 a) Draw astem and leaf diagram to show these results.
The data is not in order sothe |rst step isto draw a rough diagram.
All values are two digit so split each so that the |rst (tens) digit is a stem and th

FAQs

What is a stem-and-leaf diagram and why is it useful?

A stem-and-leaf diagram is a simple way of showing data in order. It helps you see patterns easily and is especially useful for finding the median.

How do you draw a stem-and-leaf diagram from two-digit data?

Split each value into stems (tens digit) and leaves (units digit). If the data is not already in order, start with a rough diagram, then arrange stems and leaves in ascending order and add a key.

How do you find the median from a stem-and-leaf diagram?

Cross out the lowest and highest values first, then continue crossing out until you reach the middle. If two values remain, take the midpoint between them.

Oct 26, 2026

Upload by Aditya